Pool Calendar
When to open, when to close, and when to winterize before the first frost. Computed for your exact place from the 30-year climate record at your nearest station.
Showing Denver. Search for your own town, or use your location.
Open, close, and a ten-day winterize reminder.
Opening weekend watch: Check the live forecast and work windows for your place on the Weather page before you pull the cover off.
Pool dates for major cities
Computed from each city's own station normals. Your town's dates may differ; use the planner above for your exact place.
| City | Open around | Close / winterize | Season | |
|---|---|---|---|---|
| New York, NY | May 1 | October 27 | 179 days | |
| Los Angeles, CA | Year-round | No hard close | Year-round | |
| Chicago, IL | May 8 | October 14 | 159 days | |
| Houston, TX | February 16 | December 18 | 305 days | |
| Phoenix, AZ | February 24 | December 8 | 287 days | |
| Philadelphia, PA | April 29 | October 23 | 177 days | |
| San Antonio, TX | February 27 | November 18 | 264 days | |
| San Diego, CA | April 4 | December 14 | 254 days | |
| Dallas, TX | March 18 | November 14 | 241 days | |
| Austin, TX | February 27 | November 23 | 269 days | |
| Miami, FL | Year-round | No hard close | Year-round | |
| Tampa, FL | Year-round | No hard close | Year-round | |
| Atlanta, GA | April 7 | October 30 | 206 days | |
| Seattle, WA | May 22 | October 10 | 140 days | |
| Denver, CO | May 21 | October 4 | 136 days | |
| Boston, MA | May 17 | October 14 | 150 days | |
| Las Vegas, NV | March 13 | November 17 | 250 days | |
| Portland, OR | May 19 | October 11 | 145 days | |
| Minneapolis, MN | May 17 | September 28 | 134 days | |
| Detroit, MI | May 20 | October 5 | 138 days | |
| Nashville, TN | April 9 | October 24 | 198 days | |
| Charlotte, NC | April 7 | October 24 | 200 days | |
| Honolulu, HI | Year-round | No hard close | Year-round | |
| Anchorage, AK | June 26 | August 26 | 61 days |
Method: monthly mean temperature normals anchored mid-month, linear interpolation across 59F (open) and 55F (close), capped ten days before first frost. Read the full methodology.
Field notes
The dates above are the 30-year average. This is the pool season people nearby are actually having. Add what you are seeing, read what your neighbours saw.
Set your place above to read and add notes for your town.
No notes here yet. If you garden or live nearby, be the first.
Questions, answered plainly
When should I open my pool?
Open once the monthly mean temperature has settled above about 59F and nights are reliably mild. Across the South that is often April; in the Mid-Atlantic and Midwest, mid to late May; in the Northeast and Mountain West, late May into June. In the Sun Belt the season runs most of the year. The date is computed from the 30-year NOAA climate record at your nearest station, not a national average.
When should I close and winterize my pool?
Close while the water is still warm enough to winterize properly, but no later than about ten days before the first hard frost. The tool above gives both the temperature-based close window and the frost hard-stop for your place. A freeze in the plumbing is the expensive mistake; the winterize date is the one to put in your calendar.
Can I keep a pool open year-round?
Across much of the South and the desert Southwest, yes, where winter monthly means stay high enough that the water rarely cools below about 55F. Farther north the answer is no; the tool flags the places where year-round is realistic.
How is the pool season length calculated?
From the spring crossing of about 59F to the earlier of the fall crossing of about 55F or ten days before the average first frost. It is a climate average, not a guarantee: watch the forecast and adjust for the season.