Pool season · New Hampshire
Manchester Pool Season: the Year on One Bar
Last updated: July 15, 2026 · dates · water temp
Manchester's whole pool calendar, condensed: when the water warms, when it cools, and where today falls between those edges. Use the opening guide and closing guide for the step-by-step work; keep this page for the dates.
Reading it takes ten seconds: 52 dots, one per week. Solid teal is Manchester's swim season; the hollow teal run before it (May 11 to June 1) is when to open; the hollow amber run after is when to close, with September 29 as the deadline; gray is the covered season. Today's marker shows where you stand in that cycle right now.
The Manchester pool calendar
Opening — target May 18
Target May 18; the practical window runs May 11–June 1, and the 7-day mean crosses the 61°F threshold around June 1. Cold-water starts are the cheap ones.
Closing — deadline September 29
Hold the cover until September 19, then winterize by September 29, a week ahead of the October 11 freeze normal. Late and cold beats early and warm.
Estimated water temperature by month
Monthly averages of the site's water model run on Manchester's own normals — the shape of a typical year, not a forecast. The widget above shows where the current year actually sits.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|
| 25° | 23° | 29° | 40° | 52° | 62° | 70° | 70° | 67° | 56° | 44° | 34° |
The curve peaks near 71°F — comfortable-water months here usually involve a heater or a solar cover.
Email me when Manchester hits the closing window
Data: NOAA 1991–2020 climate normals via Massabesic Lake (2.6 mi); live outlook by Open-Meteo. Attribution: sources · assumptions: methodology.