Connecticut Pool Season: Opening & Closing Dates by City

Local dates for every featured Connecticut city — when the water warms up, when it cools off, and how long the season actually lasts.

City Opening window Closing window Season
Hartford May 20 – Jun 9 Sep 6 – Sep 25 ≈ 110 days
New Haven May 27 – Jun 16 Sep 6 – Sep 26 ≈ 104 days

Windows show the stretch when each city's daily average passes through the low-to-mid 60s°F (1991–2020 NOAA records, nearest station to each city). Click a city for its month-by-month table and full season notes.

Season geography

Across Connecticut's featured cities, typical openings spread from May 30 to Jun 6, closings from Sep 17 to Sep 18, and the unheated season runs 104–110 days depending on where you are. Elevation, coastal water, and urban heat all pull real dates around, which is exactly why a state-level answer isn't enough.

For your exact town, the pool season lookup takes a ZIP code. Opening day itself is a chemistry job — the dosing calculator turns your first test reading of the year into exact amounts.

Connecticut planning pages

When to open — Connecticut When to close — Connecticut All states →