Pool Month-by-Month Planner
What a Phoenix pool needs in each month, from water temperature and chemistry to equipment and covers, with a printable plan and calendar reminders.
Choose a month
Every month is shown. Click a month to narrow the list to it; click it again to see the whole year at once.
What to show
16 tasks across the year, 3 of them marked critical.
Your ticks stay in this browser and are never uploaded. The calendar file is built on your own device.
This month
n/a
The air the pool sits in, month by month, from the climate normals, not the water temperature, which this tool does not measure.
Water temperature, by kind of swimmer
The model code does not set one comfortable temperature; it sets a band per kind of swimmer. A pool in high summer here leaves the recreational bands and reaches the range the code reserves for therapy, all on its own.
- Below 78 °F Cooler than the lap range
Below the model code’s range even for lap swimmers. Fine for a short dip on a hot day; brisk for children and older adults, and the point at which most people stop swimming and only look at it.
U.S. Centers for Disease Control and Prevention, Model Aquatic Health Code (water temperature guidance) - 78–82 °F Lap swimming and swim teams
The range the code gives for swim teams and lap swimming. Cool enough to swim hard in without overheating, which is why competitive water is kept here.
U.S. Centers for Disease Control and Prevention, Model Aquatic Health Code (water temperature guidance) - 83–86 °F Recreational swimming
The range the code gives for multi-use and recreational water and for children’s fitness. This is the band most household pools aim for.
U.S. Centers for Disease Control and Prevention, Model Aquatic Health Code (water temperature guidance) - 87–90 °F Above the recreational band
Warmer than the code’s recreational range. Only the instructional and therapeutic categories sit this warm, and a Phoenix pool reaches it on its own in July and August.
U.S. Centers for Disease Control and Prevention, Model Aquatic Health Code (water temperature guidance) - Above 90 °F Therapy-water temperature
At or above the code’s therapy and rehabilitation range. Not a recreational swimming temperature, and the point at which a Phoenix pool stops losing heat to the night air at all.
U.S. Centers for Disease Control and Prevention, Model Aquatic Health Code (water temperature guidance)
The chemistry routine, summer and winter
The ranges do not change with the season; the demand on them does. Warm water and heavy use are what a residual is spent against, and cool water is where it lasts.
pH pH 7.0–7.8
In season Hold the middle of the range. The CDC gives 7.0–7.8 as the balance between how well chlorine kills and how long the equipment lasts; Maricopa County’s enforceable range for public pools is the narrower 7.2–7.8.
Off season The same range, with less drift: demand falls with the temperature.
U.S. Centers for Disease Control and Prevention, Home Pool and Hot Tub Water Treatment and TestingFree chlorine Free chlorine of at least 1 ppm
In season The CDC’s floor is 1 ppm, and 2 ppm if a stabilised chlorine product or cyanuric acid is in the water. Arizona sun and heat burn chlorine off quickly, which is why the CDC says to test at least twice a day in season.
Off season The same floor. Free chlorine lasts longer in cool water, so the winter job is keeping it from drifting too high rather than chasing it upward.
U.S. Centers for Disease Control and Prevention, Home Pool and Hot Tub Water Treatment and TestingTotal alkalinity Total alkalinity 60–180 ppm
In season The county’s range for pools and spas. Alkalinity buffers the pH, so it is the measurement that stops the pH swinging on a hot, high-use day.
Off season The same range; check it while the water is otherwise quiet.
Maricopa County Environmental Services, Swimming Pools Management, Environmental Health Code Chapter VI, Section 2Testing routine Test the water at least twice a day in season
In season The CDC’s instruction is to test chlorine and pH at least twice a day and more often when the pool is busy. A DPD test kit reads more accurately than strips, and above about 10 ppm chlorine a test can bleach out and read falsely low.
Off season Demand drops with the temperature, but a pool in November still needs the same two readings. The county requires public pools to test daily and keep a twelve-month log; a household pool is the owner’s call, made against the same ranges.
U.S. Centers for Disease Control and Prevention, Home Pool and Hot Tub Water Treatment and TestingThe year, month by month
January 67.6° / 46° F
Normal high 67.6 °F, normal low 46 °F, and about 0.4 nights below freezing.
- Watch the overnight forecast and keep the water moving Critical January is one of only two months whose nights reach freezing here, and the record puts roughly half a night below 32 °F in an average January. Moving water is what keeps a pipe or a pump housing from splitting, so a freezing night is a night the pump runs. No Arizona agency publishes a pool-specific freeze procedure; the timing comes from the record and the practice is what the equipment needs. NOAA NCEI U.S. Climate Normals 1991–2020, monthly, Phoenix Sky Harbor (USW00023183)
- Hold the winter chemistry at the season’s lower demand The water is at its coolest and the demand on chlorine is at its lowest, so the winter job is keeping the ranges steady rather than chasing them. Test the same two readings (pH and free chlorine) and keep the pH in the range that protects the equipment. U.S. Centers for Disease Control and Prevention, Home Pool and Hot Tub Water Treatment and Testing
February 70.8° / 49° F
Normal high 70.8 °F, normal low 49 °F, and about 0.1 nights below freezing.
- Have the pump and filter looked at before the season February is the calm month, which is exactly why it is the right one for a service visit. A pump seal, a cracked O-ring or a heater that has sat idle all winter is cheaper found now than on the first hot week of May. Maricopa County Environmental Services, Swimming Pools Management, Environmental Health Code Chapter VI, Section 2
March 78.1° / 54.5° F
Normal high 78.1 °F, normal low 54.5 °F, and no normal nights below freezing.
- Note the filter’s clean pressure before the load arrives A pressure gauge only tells you something against a baseline. Record the reading on a freshly cleaned filter now, while the water is still quiet, and the rise that means “clean me” later in the year is a number rather than a guess. Maricopa County Environmental Services, Swimming Pools Management, Environmental Health Code Chapter VI, Section 2
April 85.5° / 60.8° F
Normal high 85.5 °F, normal low 60.8 °F, and no normal nights below freezing.
- Clean the cartridges or backwash, and set the summer run time The water starts to warm this month and the pump needs to run longer to turn it over. Clean the filter as the season opens, and move the run into the cooler hours of the morning and evening. Maricopa County Environmental Services, Swimming Pools Management, Environmental Health Code Chapter VI, Section 2
May 94.5° / 69.5° F
Normal high 94.5 °F, normal low 69.5 °F, and no normal nights below freezing.
- Check the barrier, the gate and the drain covers before the heavy season Critical Before the pool fills with people, walk the barrier and the gate latch, and look at the drain covers. The CDC’s drowning-prevention work is blunt about why: drowning is quiet and fast, and it is the leading cause of death for children aged one to four. This is the month to fix what the winter loosened. U.S. Centers for Disease Control and Prevention, Drowning Prevention
- The water warms fast: expect to raise the pump run again The normal high jumps to the mid-90s in May, and the water follows it up. As the water passes into the low 80s the pool is comfortable, the load on chlorine rises, and the run time set in April wants another look. NOAA NCEI U.S. Climate Normals 1991–2020, monthly, Phoenix Sky Harbor (USW00023183)
June 104.2° / 78.6° F
Normal high 104.2 °F, normal low 78.6 °F, and no normal nights below freezing.
- Peak sun burns chlorine off fastest: test twice a day June is the sunniest and driest month of the year, and both work against a chlorine residual. The CDC’s in-season instruction is to test pH and chlorine at least twice a day. If the water is being kept with a stabilised product, the CDC’s floor rises to 2 ppm rather than 1. U.S. Centers for Disease Control and Prevention, Home Pool and Hot Tub Water Treatment and Testing
July 106.5° / 84.5° F
Normal high 106.5 °F, normal low 84.5 °F, and no normal nights below freezing.
- The water is at its warmest, and past about 90 °F it is above every recreational range July is the hottest month here, with a normal high of 106.5 °F, and a pool gains heat all day and gives little of it back overnight. Once the water passes about 90 °F it has left the recreational band the model code gives and entered the range the code reserves for therapy. U.S. Centers for Disease Control and Prevention, Model Aquatic Health Code (water temperature guidance)
- Warm water and heavy use are the hardest combination for chemistry Warm water with a full pool is when a residual is used up fastest and pH drifts most. Test twice a day, keep free chlorine at or above the floor, and keep pH inside the range: the CDC notes chlorine kills far more slowly as pH climbs. U.S. Centers for Disease Control and Prevention, Home Pool and Hot Tub Water Treatment and Testing
August 105.1° / 83.6° F
Normal high 105.1 °F, normal low 83.6 °F, and no normal nights below freezing.
- After a storm, clear the debris and retest before anyone swims Monsoon rain and wind leave a pool full of leaf litter and dirt, both of which consume chlorine. The CDC lists dirt and debris carried in by swimmers among the things that drop a residual. Clear it, then test before the pool goes back into use. U.S. Centers for Disease Control and Prevention, Home Pool and Hot Tub Water Treatment and Testing
- Clean the filter again at the height of the season This is the month the filter earns its keep and the month it loads fastest. Watch the gauge against the clean baseline recorded in March, and clean it before the pressure climbs well past it. Maricopa County Environmental Services, Swimming Pools Management, Environmental Health Code Chapter VI, Section 2
September 100.4° / 78.1° F
Normal high 100.4 °F, normal low 78.1 °F, and no normal nights below freezing.
- Still hot, still testing: the season has not turned yet September’s normal high is still 100 °F, and the storm season is only just ending. Demand has not fallen yet, and the twice-a-day habit is worth keeping until the water starts to cool in October. NOAA NCEI U.S. Climate Normals 1991–2020, monthly, Phoenix Sky Harbor (USW00023183)
October 89.2° / 65.6° F
Normal high 89.2 °F, normal low 65.6 °F, and no normal nights below freezing.
- Comfortable water and cooler nights: begin to trim the pump run The normal high drops into the upper 80s and the nights fall away from it. The water is at its most pleasant of the year, and the run time set for July can start coming down toward the winter schedule. NOAA NCEI U.S. Climate Normals 1991–2020, monthly, Phoenix Sky Harbor (USW00023183)
November 76.5° / 53.7° F
Normal high 76.5 °F, normal low 53.7 °F, and no normal nights below freezing.
- The water slips below the lap range: set the winter schedule November’s normal low is 53.7 °F, and the water follows the nights down. Below the lap-swim range the pool is a colder swim than most people want, and the filtration schedule can settle to fewer, cooler hours. NOAA NCEI U.S. Climate Normals 1991–2020, monthly, Phoenix Sky Harbor (USW00023183)
December 66.2° / 45.3° F
Normal high 66.2 °F, normal low 45.3 °F, and about 0.1 nights below freezing.
- The coldest water of the year, and the freeze watch is now Critical December and January are the only months whose nights reach freezing, and December averages about a tenth of a night below 32 °F. The freeze protection set up in the autumn is the thing being tested now: on a freezing night the pump runs, and the equipment that would freeze is the equipment to check first. NOAA NCEI U.S. Climate Normals 1991–2020, monthly, Phoenix Sky Harbor (USW00023183)
A pool here is two problems in one year
Most pool advice is written for a place with one hard season, and it does not fit Phoenix. A Valley pool is not closed and drained for the winter; it runs all year, and the year splits into two problems that have little to do with each other. From May to September the water gains heat faster than it can shed it, the sun burns chlorine off quickly, and the water can climb past every recreational range the model code publishes. From November to February the water is cool, demand collapses, and the only real risk is the handful of nights a year that reach freezing. This planner is built to show both halves, because a household that only reads the summer half is the household that splits a pump housing in January.
The water temperature, and why it is bands rather than a number
The CDC keeps a model code for aquatic facilities, and the useful thing about it for a household is that it does not set one comfortable temperature. It sets a band per kind of swimmer: a cooler range for swim teams and lap swimming, one a few degrees above that for recreational and multi-use water, and warmer ranges again for instructional and therapeutic use. Reading that table is what makes “the pool is warm” mean something specific. It also makes the Phoenix summer legible: July’s normal high is 106.5 °F, the overnight low holds in the mid-eighties, and once the water passes about 90 °F it has left the recreational bands altogether and entered the range the code reserves for therapy. That is not a failure of maintenance; it is the climate, and it is why the article below spends its time on the night temperature rather than the day.
The chemistry, which is the same ranges all year
The published ranges do not change with the season. The CDC’s home-pool guidance puts pH at 7.0–7.8 and free chlorine at a floor of 1 ppm, rising to 2 ppm where a stabilised product or cyanuric acid is in the water, and it says to test chlorine and pH at least twice a day in season and more often when the pool is busy. Maricopa County’s enforceable ranges for public pools are the narrower pH 7.2–7.8 with free chlorine 1–5 ppm and total alkalinity 60–180 ppm, tested daily and logged for twelve months. Neither set is changed by the calendar. What changes is the demand on them: a warm, busy pool spends a residual fast and drifts in pH, and a cool, quiet one holds both with far less attention. That is the whole of the seasonal difference, and it is why the chemistry block above gives one set of ranges and two ways of minding them.
The freeze items, and the thing no agency publishes
This is the part of the page to be most careful with, so it is worth stating plainly: no Arizona or federal agency publishes a pool-specific freeze procedure. What the record does give is the timing. The monthly normals for Phoenix Sky Harbor put the only nights below 32 °F in December and January (roughly half a night in an average January, a tenth of one in December, and none in any other month) and that is what sets the freeze watch. What protects the equipment is physics rather than a rule: water expands as it freezes, the parts of a pool system with water sitting in them are the parts that split, and moving water does not sit still long enough to freeze. So the practice is a running pump on those nights, and the page presents it as this site’s explanation of what the equipment needs, not as an agency’s instruction. The distinction matters because a reader who mistakes the one for the other will go looking for the agency page and not find it.
Why the tool asks for no pool volume
Every other pool tool on the web asks for your gallons, because it wants to hand you a dose: so many ounces of acid, so many pounds of shock. This one does not, and that is deliberate. Dosing is arithmetic on numbers a household should take from a test kit and a product label, and a table of amounts printed without knowing the volume, the sanitiser type or the current reading would be a made-up answer with a confident face. What this planner gives instead is the routine (which reading to take, how often, against which range, and what the season does to the demand) and leaves the arithmetic to the kit. Being useful without being authoritative about a number this tool cannot know is the point.
Where this plan stops
It does not know your pool, your equipment or your water, and it does not measure anything. It describes a typical year at one urban weather station and lays the published care routine over it, month by month, each item with the source that says why. The safety layer (the barrier, the gate, the drain covers) is on the list because it belongs at the front of the season rather than the back, but a list does not supervise a child, and the drowning-prevention material linked above is the authority on that question rather than this page.
- U.S. Centers for Disease Control and Prevention: Home Pool and Hot Tub Water Treatment and Testing
The chemistry routine: pH 7.0–7.8, free chlorine of at least 1 ppm and 2 ppm where a stabilised product is used, and the instruction to test chlorine and pH at least twice a day in season and more often when the pool is busy.
- U.S. Centers for Disease Control and Prevention: Model Aquatic Health Code
The water-temperature bands, by kind of swimmer: the lap and swim-team range, the recreational and multi-use range, and the instructional and therapeutic ranges above them that a Phoenix pool reaches on its own in high summer.
- Maricopa County Environmental Services: Swimming Pools Management, Environmental Health Code Chapter VI, Section 2
The county’s enforceable ranges for public pools and spas (free chlorine 1–5 ppm, pH 7.2–7.8, total alkalinity 60–180 ppm), the daily testing and twelve-month log, and the equipment and filter guidance the household tasks are modelled on.
- U.S. Centers for Disease Control and Prevention: Drowning Prevention
The safety layer that runs before the season: the barrier, the gate latch and the drain covers, and the fact that drowning is the leading cause of death for children aged one to four.
- NOAA NCEI U.S. Climate Normals 1991–2020, monthly, Phoenix Sky Harbor (USW00023183)
The month-by-month air temperature behind every task: the normal highs and lows, and the counts of nights below 32 °F that put the freeze risk in December and January and nowhere else.
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.
- The page knows nothing about your pool. There is no volume, no surface area and no sanitiser type in any calculation here, and so there are no chemical quantities: no gallons of acid, no pounds of shock. Dosing a pool is arithmetic on numbers this tool never asks for, and a table of doses printed without them would be worse than no table.
- The water temperature is described in bands, not measured. Nobody is standing in your pool; the bands are the ranges the model code publishes by kind of swimmer, and the month-by-month context is the air the pool sits in, not the water in it. A pool’s actual temperature depends on its depth, its shade, its cover and its use, none of which this tool knows.
- The freeze guidance is this site’s wording, not an agency’s. No Arizona or federal agency publishes a pool-specific freeze procedure. The timing is from the record (December and January are the only months whose nights reach freezing at Phoenix Sky Harbor) and the practice of keeping the water moving is what the equipment needs. It is written that way on the page rather than dressed up as official instruction.
- The chemistry figures are the ranges for public pools and spas, which is a stricter bar than a household needs. The county’s ranges are enforceable on commercial pools; a home pool is the owner’s to run. They are used here because they are the published numbers, and because the CDC’s home-pool guidance and the county’s commercial ranges agree closely enough to be useful together.
- Testing guidance is a frequency, not a method. The CDC says to test chlorine and pH at least twice a day in season; it also notes that a test can bleach out and read falsely low above about 10 ppm chlorine. A DPD kit reads more accurately than strips. If a reading is impossible to interpret, the answer is a pool professional rather than another dose.
- The task list is a household one. It does not cover a pool heater’s service schedule, a salt cell’s cleaning interval, in-floor cleaning systems, or the specific maintenance a spa shares with a pool. The manufacturer’s manual for each of those outranks anything here.
- Like the cooling scheduler, this tool stores only which items you have ticked, in this browser, under the one key the two tools share. The two keep their ticks apart by prefixing every item, so planning the pool does not clear the cooling list.
- Nothing on this page is a safety guarantee. The barrier, the gate and the drain covers are items on a list, and a list does not watch a child. The CDC’s drowning-prevention material is the authority on supervision, and it is linked above because the safety layer matters more than the other four combined.