PoolWindow

Pool season · Connecticut

New Haven Pool Season: the Year on One Bar

Last updated: July 15, 2026 · dates · water temp

New Haven'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.

J F M A M J J A S O N D today (build date)

off-season opening window swim season closing window

Reading it takes ten seconds: 52 dots, one per week. Solid teal is New Haven's swim season; the hollow teal run before it (May 4 to May 25) is when to open; the hollow amber run after is when to close, with October 9 as the deadline; gray is the covered season. Today's marker shows where you stand in that cycle right now.

The New Haven pool calendar

May 11open by
October 9close by
5880°F+ days
74°Fwater peak

Opening — target May 11

Target May 11; the practical window runs May 4–May 25, and the 7-day mean crosses the 61°F threshold around May 25. Cold-water starts are the cheap ones.

Full opening guide

Closing — deadline October 9

The window opens September 29 once water leaves the algae zone; the model deadline is October 9, a week ahead of the October 27 freeze normal.

Full closing guide

Where the water sits today

SEASONAL VIEW

Estimated unheated pool water temp (site model, ±5°F). The live estimate loads in your browser from Open-Meteo air temperatures; in a typical year New Haven water runs about 30°F at its winter floor and 74°F at its summer peak.

40 45 50 55 60 65 70 75 80 85 58 open 65 algae

Estimated water temperature by month

This is New Haven's typical-year water curve: the same EWMA model as the live widget, run on the 1991–2020 normals instead of this week's weather.

Site-model seasonal water estimates for an unheated in-ground pool near New Haven Tweed Airport — ±5°F, see methodology.
JanFebMarAprMayJunJulAugSepOctNovDec
33°31°35°44°54°64°72°74°70°60°49°40°

The curve peaks near 74°F — comfortable-water months here usually involve a heater or a solar cover.

Data: NOAA 1991–2020 climate normals via New Haven Tweed Airport (3.8 mi); live outlook by Open-Meteo. Attribution: sources · assumptions: methodology.