Monsoon Prep Checklist Builder
Build a printable monsoon preparation checklist for your home type, vehicles and pets, with reminders you can add to a calendar as an .ics file.
What your household has
Every list includes the house and the people in it. The three below add the items that only apply if you have them.
41 items, of which 17 are marked as safety-critical and are never hidden by the filters.
Your ticks stay in this browser and are never uploaded. Nothing on this page is sent anywhere.
Your list
41 items
Grouped by when they have to happen. Tick them off as you go. The list is saved in this browser, so you can come back to it.
When each part of the season happens
Three windows that overlap and one deadline that does not move. The insurance window closes on May 16 (thirty days before the season opens) and it is the only date here that cannot be met late.
Season dates from the National Weather Service’s Phoenix office. The insurance deadline is this site’s subtraction: thirty days back from 15 June, using the waiting period Maricopa County and FEMA both publish. It is arithmetic, not a published date.
Before the season May and early June
Work on the building and the paperwork. Everything here needs dry weather and, in the case of flood insurance, thirty days of it.
- Buy or renew flood insurance, and start the clock now Safety-critical This is the only item on the list that cannot be done at the last minute. There is a thirty-day waiting period before a policy takes effect, so a policy bought when a storm is in the forecast will not cover that storm: the county says so in as many words. “When a storm is in the forecast, it’s too late to get a flood policy!” Maricopa County flood insurance
- Clear the roof drains and scuppers Safety-critical A flat or low-slope roof drains through scuppers that silt up between storms. When they block, the water has nowhere to go but down through the roof. “Clean out roof drains or scuppers to prevent accumulation of rain water on the roof.” City of Phoenix monsoon
- Thin the trees and cut back overgrowth Thinning matters more than shortening. A thinned canopy lets the wind through; a dense one catches it and turns the whole tree into a lever. Dead limbs are the ones that come down on a roof. “Thin out trees and trim down overgrown vegetation.” City of Phoenix monsoon
- Clear the drywells on the property A drywell is a pit that holds storm water until the ground takes it. One that has filled with silt over the years holds almost nothing, and the water it should have taken goes somewhere else. “Clean out drywells on your property so there is safe place for the water to collect.” City of Phoenix monsoon
- Re-grade the landscaping so water runs away from the building The cheap fix is a rake and an afternoon. Water should leave the yard or pond somewhere that is not against the wall, and the ground should fall away from the slab rather than toward it. “Repair landscaping to ensure water will run away from your building.” City of Phoenix monsoon
- Build or restock the emergency kit Safety-critical The county’s figure is three days. The utility’s figure is a gallon of water per person per day, which for three days is three gallons each, more than most people store. Check the first-aid kit contents rather than counting the box. “Bottled water: Have at least 1 gallon per person, per day.” SRP storm preparation
- Find the shut-offs for electricity, water and gas Safety-critical Find them in daylight and dry weather, and show everybody in the house. This is a five-minute job that is impossible to do in the dark with water on the floor. “Know where to find each utility shut off: electricity, water and gas.” SRP storm preparation
- Learn to open the garage door by hand An automatic door with no power is a wall. The release is usually a red cord, and the first time anybody pulls it should not be during an outage. “If you have an automatic garage door, learn how to open it manually” APS storm preparation
- Back up your data The city names this as a monsoon task, which is a reminder that water and electronics are the pairing that costs the most to replace. “Back up all data in case your computer or servers become damaged.” City of Phoenix monsoon
- Put the electronics behind surge protection Outages here end with the power coming back on, and the surge at restoration is what kills equipment. Both the utility and the federal guidance name this as a preparation rather than a response. “Install surge protectors to safeguard valuable electronic equipment” SRP storm preparation
- Repair torn window and door screens Mosquitoes breed in the standing water every storm leaves behind, and a torn screen is the way they get in. The county’s guidance treats screens as part of storm preparation rather than a separate job. “REPAIR or replace damaged window and door screens” Maricopa County Fight the Bite
- Write the family plan down Where everybody meets, who collects the children, who takes the pets. The county’s instruction is to create one; the value is in having agreed it before the phones are down. “Create a family plan.” Maricopa County monsoon guidance
- Replace the wipers and check the tyres The county puts this on its monsoon list, and the reason is the first ten minutes of a storm: the rain arrives faster than the drainage and the road is at its slickest right then. “Change your windshield wipers. Check your tires.” Maricopa County monsoon guidance
When a storm is forecast 24 to 48 hours out
The last chance to move things. Nothing on this list takes more than an hour, and all of it is undone by waiting for the first rumble of thunder.
- Bring in the outdoor furniture Anything loose becomes a projectile in the outflow of a storm, which is the wind that arrives ahead of the rain. Patio chairs go into the garage, not against the wall. “Bring in outdoor furniture and move important indoor items to the highest possible floor.” City of Phoenix monsoon
- Secure anything that could reach a power line The utility names umbrellas, kiddie pools and trampolines specifically, and gives the reason: they get swept up and end up in the lines, which is how a storm in one street becomes an outage in another. “Umbrellas, kiddie pools and even trampolines can be swept up by wind and end up in power lines, causing outages.” APS storm preparation
- Move valuables to a higher floor The federal guidance says higher levels, and the city says the highest possible floor. Both mean the same thing: water that gets in finds the lowest thing first. “Move valuables to higher levels” Ready.gov floods
- Sandbag the low entrances Fill the bags half to two-thirds full, no more: a bag packed solid will not settle against the one below it. Stack them in a brick pattern and put them where water actually arrives: the front door and any low entrance, not evenly around the house. “Stack sandbags in a brick pattern… Focus on the entrances areas of the house like front doors and low entrances.” Maricopa County monsoon guidance
- Deploy a reusable flood barrier if you have one The city hands out self-activating barriers that open on contact with water and divert flow the way sandbags do. They go down in the flood-prone spots before you leave for work, not after you get home. “The barriers deploy within minutes on contact with water and divert flow like sandbags.” Phoenix monsoon resources
- Plan where the pets will be The county’s storm instruction is simply to bring them indoors and make sure they have water. The forecast day is the day to decide which room, because a frightened animal is not going to be caught once it starts. “Bring pets indoors. Make sure they have plenty of water” Maricopa County monsoon guidance
- Charge the phones, the power banks and the radio An outage in a monsoon is measured in hours, and a phone at 20% is the thing that turns a manageable evening into a bad one. “Battery-powered phone charger: Keep your mobile phone charged during an outage.” SRP storm preparation
- Change any plan that involves a wash or a stream Safety-critical The forecast office is direct about this one, and it covers people who are not in the valley at all: a campsite that is dry when you pitch the tent can be a channel two hours later from rain you never see. “Do not camp overnight or park your vehicle along/near streams and washes during the monsoon.” NWS Phoenix monsoon safety
During the storm While it is happening
Nothing on this list is a task. They are things not to do, and the two that matter most are both about driving.
- Do not drive into a flooded roadway Safety-critical The Phoenix forecast office states this without qualification, and the depth figures are on the wash-crossing tool. There is no depth at which any agency endorses it. “Never drive into a flooded roadway” NWS Phoenix monsoon safety
- Do not drive around a barricade Safety-critical A barricade is placed at a specific crossing because that crossing is the problem. Both the county and the forecast office put this in capitals, and Arizona law attaches liability to the driver who goes past one. “NEVER drive around barricades” Maricopa County monsoon guidance
- Keep children and pets away from washes and storm drains Safety-critical The forecast office gives this as guidance for after any rainfall, not only during it. A wash runs for hours after the rain that filled it has stopped, and a storm drain is a vertical drop with water in it. “Never allow children to play near washes or storm drains after any rainfall.” NWS Phoenix monsoon safety
- In a dust storm: pull off, stop, lights off Safety-critical The order is the whole of it. Pull as far off the pavement as you can, stop, and turn off every light including the hazards: the reason is that a driver behind you will otherwise steer toward your tail lights and into your car. Stay belted in until it passes. “Make sure all of your lights are off when you park off the roadway.” NWS Phoenix monsoon safety
- Stay in until thirty minutes after the last thunder Safety-critical The forecast office gives both halves of the rule: thunder means you are close enough to be struck, and the all-clear is thirty minutes after the last rumble rather than after the rain stops. Indoors, keep off the plumbing and the wiring. “Wait there until 30 minutes AFTER the last rumble of thunder is heard.” NWS Phoenix monsoon safety
- Stay 100 feet from a downed power line Safety-critical Both utilities give a hundred feet and say electricity can travel through the ground, so the distance matters even without a spark. Note that City of Mesa publishes twenty feet; where a city and the utility that owns the line disagree, the utility’s number is the one to keep. “If you see a downed power line, stay at least 100 feet away.” SRP storm preparation
- During an outage, switch off the appliances Turning off the air conditioner, the computer and the major appliances means they do not all start at once when power returns, and it means nothing is running when the surge arrives. Leave one light on so you know when it does. “Turn off all lights except one to indicate when the power has been restored.” SRP storm preparation
- Get out of the pool and stay out Safety-critical Lightning strikes water, and a pool is the tallest thing in most back yards. The utility guidance is blunt about it, and the thirty-minute rule applies here too. “Do not swim during a storm. Lightning can strike bodies of water.” SRP storm preparation
- In high wind, take an interior room without windows Safety-critical Downburst winds arrive ahead of the rain and are the reason roofs come off in a storm that drops almost no water. Mobile homes should be abandoned rather than ridden out. “Shelter in a central interior room without windows.” City of Mesa severe weather
- Check on anybody who lives alone The county puts this on its monsoon list next to the flooding advice, and the reason is that the storm and the heat arrive together. An outage in July takes the air conditioning with it. “Check on family and friends who are at high risk for heat-related illness” Maricopa County monsoon guidance
After the storm Once it has passed
The order matters here more than anywhere else on the page. The county puts calling your insurer first for a reason.
- Return home only when you are told it is safe Barricades stay up after the water goes down, because the road underneath may not be there. Both the city and the federal guidance say the same thing, and neither offers an exception. “Return home only when authorities say it is safe.” City of Phoenix monsoon
- Call your insurance company first Safety-critical This is the first of the county’s five steps after a flood, ahead of removing the water. The order is the advice: the claim is easier to make before the evidence has been moved or thrown away. “Call your insurance company.” Maricopa County monsoon guidance
- Photograph everything before you clean up Both the city and the county name this, and both put it before the work. Wide shots of each room, then close shots of what was damaged, taken before anything is carried out. “Photograph damage to your property for insurance purposes.” City of Phoenix monsoon
- Wear gloves and boots, and stay out of the water Safety-critical Floodwater in a desert carries silt, sewage and sharp debris, and the federal guidance names all three reasons to keep your skin out of it while you work. “Avoid wading in floodwater, which can be contaminated and contain dangerous debris.” Ready.gov floods
- Do not touch electrical equipment that is wet Safety-critical Including anything you are standing in water to reach. The federal guidance is the shortest sentence on this list and the most important one after a flood. “Do not touch electrical equipment if it is wet or if you are standing in water.” Ready.gov floods
- Run any generator outdoors and away from windows Safety-critical Carbon monoxide from a generator run in a garage or against a wall kills people after storms every year, and it does it without a smell. “Use a generator or other gasoline-powered machinery ONLY outdoors and away from windows.” Ready.gov floods
- Watch the clock on the refrigerator and freezer Four hours for a refrigerator, forty-eight for a full freezer, and forty degrees as the line where food gets thrown out. The federal guidance puts it plainly: when in doubt, throw it out. “The refrigerator will keep food cold for about four hours.” Ready.gov power outages
- Check anything that needed refrigeration The federal guidance is specific: after a day without power, discard medication that should have been refrigerated. Ask a pharmacist rather than deciding from the label. “If the power is out for more than a day, discard any medication that should be refrigerated” Ready.gov power outages
- Tip and toss the standing water Plant pots, bird baths, buckets and fountains are where the mosquitoes breed after a storm. The county’s instruction is to tip out even the smallest amounts, and to treat it as a weekly job rather than a one-off. “Tip and toss even the smallest amounts of standing water from your home and yard.” Maricopa County Fight the Bite
- Expect animals where the water was The federal guidance warns that snakes and other animals may be inside a house after a flood. In a desert city the same goes for the yard and the garage. “Be aware that snakes and other animals may be in your house.” Ready.gov floods
Things people are told to do that no agency says
These are on a great many monsoon lists and on none of the official ones this site could open. They are printed here rather than dropped, because a reader who has been told to fill the bathtub should be able to see that the advice did not come from anywhere official, and two of these are not harmless.
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Fill the bathtub before a storm
Widely repeated as storm preparation, and it is not on any Arizona or federal list this site could open.
The closest official instruction is Mesa’s, which says to store clean water in jugs in case the supply is contaminated. A bathtub is not a clean container and the water in it is not treated. If you want water stored, store it the way the guidance says.
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Tape your windows
No official source. The federal thunderstorm guidance goes the other way: shelter away from windows rather than reinforcing them.
Taping glass does not stop it breaking and it does create larger, heavier shards than an untaped pane. Arizona’s storms break windows with flying debris and wind pressure, not with the pressure drop that the taping advice was invented for.
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Open the windows before a storm to equalise the pressure
No official source. If anything, the guidance is to stay away from the windows entirely.
This one is the most likely of the four to get somebody hurt, because it puts a person at the glass at the moment the glass is most likely to fail.
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Move the car to higher ground before a storm
No official source found. FEMA says to move valuables to higher levels, and it says it about property rather than vehicles.
That is not the same as saying it is a bad idea in a specific driveway. It is saying that if you do it, you are acting on your own judgement about your own street rather than on published guidance, and doing it in a hurry, as a storm arrives, has its own risks.
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Lower the pool water or switch the pump off before a storm
No official Arizona source found. The only official pool guidance this site could open is about where drained pool water is allowed to go: the sanitary sewer, never a storm drain.
A pool whose water is drained into a storm drain is putting that water into the same channel the storm is already filling. The pool-care tool on this site covers what a monsoon actually does to pool chemistry, which is a different question.
Where every line on this list came from
A monsoon preparation list is the most copied document on the Arizona internet. Most of them cannot tell you where a given line originated, and a fair number of them contain items that no agency has ever published: advice that has been copied forward from list to list until it acquired the authority of repetition.
This one works the other way round. It was built by opening the agencies that publish monsoon guidance for this county (the city, the county, the county's public health department, the National Weather Service's Phoenix office, both electric utilities, FEMA's Ready.gov, and the City of Mesa), collecting what each of them actually says, and then writing the items out with the source attached. Most items show the agency's own words in quotation marks under this site's sentence of explanation, so the reader can see the difference between what the agency said and what this site added.
The five claims this site could not source, and why they are still on the page
Every list of this kind eventually includes filling the bathtub, taping the windows, opening the windows to equalise pressure, moving the car to higher ground, and lowering the pool. This site went looking for an official source for each of them and found none.
The temptation is to drop them silently, and the trouble with dropping them silently is that a reader who has read five other lists will notice the absence and assume this site forgot. Printing them as unsourced is the honest third option, and it is more useful than either of the other two: it tells the reader not just what to do but which parts of what they have been told came from anywhere.
Two of the five are worth being blunt about. Taping windows does not stop glass breaking and it produces larger, heavier shards than an untaped pane. Opening windows to equalise pressure is worse: it puts a person at the glass at the moment the glass is most likely to fail, and the pressure-drop explanation behind it belongs to tornado advice rather than to Arizona storms, which break windows with debris and wind load.
One deadline, and why the calendar export exists
Almost everything on this list is a job with a season rather than a day, which is why only three items carry a date on the calendar file. Flood insurance is the exception, and it is the reason the export is worth having at all.
Maricopa County publishes the rule: there is a thirty-day waiting period between buying coverage and it taking effect, and "when a storm is in the forecast, it's too late to get a flood policy". FEMA states the same thirty days nationally. Counting back from 15 June puts the deadline at 16 May, and that subtraction is this site's rather than a published date, which is why the page labels it. The other half of the reason is that homeowner policies do not cover flooding at all, and the county reports that one in four flood insurance claims comes from outside a mapped floodplain, so the map is not the boundary of the risk.
Why the filters do not hide the safety-critical items
Ticking "a car" adds the driving items and removes nothing. Ticking nothing at all still leaves a list, because the house and the people in it are on every version, and the items marked safety-critical are never filtered out by any combination of choices.
That is a small design decision with a reason. A household with no pets and no pool still has a child who might walk to the wash at the end of the street, and the item about keeping children away from washes is the one that matters most on the list. A filter that could hide it in the name of relevance would be optimising for tidiness at the cost of the only thing on the page that has to be read.
Where this list stops
It does not assess anything. It cannot tell you whether your roof drains are clear, whether your street floods, or whether your property sits in a mapped floodplain. The Flood Control District publishes the maps and this tool links to the district rather than guessing. It also assumes the household controls the building it lives in, and says nothing about what a landlord is obliged to fix.
What it does is put 41 items in front of you in the order they have to happen, sourced, filtered to what you actually have, and printable, which is the form a pre-season list has to take if it is going to be used in a garage in May rather than read once in a browser in July.
- Maricopa County: Monsoon flooding and preparedness, Flood Control District
The three-day emergency kit, the family plan, the sandbag construction, the wiper and tyre check, the barricade rule, bringing pets indoors, and the five-step order to do things in after a flood.
- City of Phoenix: Monsoon preparedness
The pre-season house work: roof drains and scuppers, thinning trees, clearing drywells, grading water away from the building, backing up data, and returning home only when it is safe.
- City of Phoenix: Monsoon resources
The reusable self-activating flood barriers the city provides, and the note that residents bring their own bags and shovels for sand.
- NOAA National Weather Service, Phoenix: Monsoon safety
Everything in the during-the-storm group that is about driving, dust, lightning and downbursts, quoted in the forecast office’s own words.
- Salt River Project: staying prepared during monsoons
The emergency supply list, the gallon of water per person per day, surge protection, the utility shut-offs, what to switch off during an outage, and the hundred-foot distance from a downed line.
- Arizona Public Service: preparing for monsoon season
Securing outdoor objects before the wind arrives (umbrellas, kiddie pools, trampolines) and learning to open an automatic garage door by hand.
- Maricopa County: Flood insurance
The thirty-day waiting period in the county’s own words, and the figure that one in four flood insurance claims comes from outside a mapped floodplain.
- FEMA: Flood insurance
The national thirty-day waiting period, cited alongside the county’s so the deadline is not a local quirk.
- Ready.gov (FEMA): Floods
Flood recovery: moving valuables up, cleanup clothing, the warning about wet electrical equipment, and running generators outdoors only.
- Ready.gov (FEMA): Power outages
Food safety after an outage (four hours for a refrigerator, forty-eight for a full freezer, forty degrees as the discard line) and the instruction to discard refrigerated medication after a day without power.
- Ready.gov (FEMA): Thunderstorms and lightning
Tree trimming before storm season, and surge protection, cited alongside the utilities’ local versions of the same advice.
- Maricopa County Public Health: Fight the Bite
Mosquito control after rain: repairing screens, and tipping and tossing even the smallest amounts of standing water.
- City of Mesa: Severe weather, family preparedness guide
The city’s high-wind shelter advice, and its twenty-foot downed-power-line distance, printed on this page as the shorter of the two figures, next to the hundred feet both utilities give.
Every figure this tool uses was read from the source named above on 11 October 2026. Anything still waiting on a check is listed in the site's data notes rather than shown here as if it were settled.
Before you rely on this
This tool works from climate normals and published guidance, not from live weather. It describes a typical day for the month or date you chose, which is useful for planning and useless as a forecast.
- This is a checklist, not an assessment. It cannot tell you whether your roof, your drainage or your street is at risk, and it does not ask. The county has a floodplain map and a Flood Control District for that question, and the tool links to the district rather than guessing.
- The list is deliberately conservative. The federal guidance names three days of supplies and the utility names a gallon of water per person per day; this tool prints the larger requirement where the two differ, on the grounds that storing too much water is cheap and running out is not.
- The dates on the calendar export are for a monsoon season, and only three items have dates at all. Everything else is a job with a season rather than a day, and pretending otherwise would produce a calendar that gets ignored by June.
- The flood-insurance deadline is this site’s arithmetic, not a published date. Thirty days back from 15 June is 16 May, and the page says so. Whether a given policy actually takes effect in thirty days is a question for the insurer, and some endorsements differ.
- Three of the four utilities and agencies here are not the authority for a specific address. Water and sewer are the city’s, power is the utility’s, drainage is the Flood Control District’s, and this page collects all of them because a household lives under all of them at once.
- Where a city and the utility that owns the equipment disagree, the page keeps both and says which one it uses. The downed-power-line distance is the case: Mesa publishes twenty feet and both utilities publish a hundred. The tool uses a hundred and prints the disagreement rather than averaging it.
- The unsourced claims are printed rather than dropped, and printing them is not an endorsement of any of them. They are there so a reader who has been told to tape their windows can see that no agency this site could open says to, instead of finding the advice silently absent from a list that claims to be complete.
- Nothing here covers commercial property, tenants’ rights, or what a landlord is obliged to fix. The checklist is written for a household that controls the building it lives in.