Pool opening · State guide
When to Open Your Pool in Arizona
Last updated: July 15, 2026 · 20 cities covered
Arizona's opening calendar spans about 127 days. The earliest model date belongs to Yuma (January 26), the latest to Flagstaff (June 2), and the statewide median lands on February 25.
Every date is the same model — two weeks ahead of the day the local 7-day mean temperature crosses 61°F — applied to each city's own NOAA normals station. Click through for the live water estimate, the full window, and the 12-step checklist.
| City | Open by | Window opens | 61°F crossing |
|---|---|---|---|
| Avondale | Feb 15 | Feb 8 | Mar 1 |
| Buckeye | Feb 15 | Feb 8 | Mar 1 |
| Casas Adobes | Mar 7 | Feb 28 | Mar 21 |
| Chandler | Feb 20 | Feb 13 | Mar 6 |
| Flagstaff | Jun 2 | May 26 | Jun 16 |
| Gilbert | Feb 25 | Feb 18 | Mar 11 |
| Glendale | Feb 23 | Feb 16 | Mar 9 |
| Goodyear | Feb 16 | Feb 9 | Mar 2 |
| Maricopa | Feb 25 | Feb 18 | Mar 11 |
| Mesa | Feb 24 | Feb 17 | Mar 10 |
| Peoria | Mar 6 | Feb 27 | Mar 20 |
| Phoenix | Feb 22 | Feb 15 | Mar 8 |
| Prescott Valley | May 4 | Apr 27 | May 18 |
| Queen Creek | Feb 25 | Feb 18 | Mar 11 |
| San Tan Valley | Feb 25 | Feb 18 | Mar 11 |
| Scottsdale | Mar 7 | Feb 28 | Mar 21 |
| Surprise | Mar 6 | Feb 27 | Mar 20 |
| Tempe | Feb 20 | Feb 13 | Mar 6 |
| Tucson | Feb 26 | Feb 19 | Mar 12 |
| Yuma | Jan 26 | Jan 19 | Feb 9 |
Dates are typical-year model outputs, not forecasts — each city guide carries the live widget that tracks the current year against them.
How to use these dates
Each "open by" date is two weeks ahead of that city's own 61°F crossing — the day its 7-day mean temperature (highs and lows averaged, from the nearest NOAA 1991–2020 normals station) reaches the level where unheated pool water starts climbing toward the 65°F algae-growth zone. Opening inside the window means starting up in cold, algae-resistant water: a single label-dosed shock instead of a green-water recovery, and a shopping trip while Arizona stores are still fully stocked.
Dates are typical-year guidance, not forecasts. A warm or late spring shifts the real-world moment by a week or two in either direction — every city guide carries a live water-temperature widget that tracks the current year against these normals, plus the full 12-step opening checklist sequenced to its local window. New to the process? Start with the generic how-to-open guide and the chemicals shopping list, then come back for your city's dates.