PoolWindow

Pool season · Massachusetts

Springfield Pool Season: the Year on One Bar

Last updated: July 25, 2026 · dates · water temp

Springfield'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.

Cool blue pool in a short-season northern climateSpringfield, MA — 78 swim days a year
J F M A M J J A S O N D today (build date)

off-season opening window swim season closing window

Each dot on the bar is one week of Springfield's typical year, colored by what the model says that week is for: gray weeks are off-season, hollow teal marks the opening window (May 3–May 24), solid teal is swim season, and hollow amber is the closing window ending October 1. The black marker is today — its position against the colors is the entire executive summary.

The Springfield pool calendar

May 10open by
October 1close by
7880°F+ days
73°Fwater peak

Opening — target May 10

Target May 10; the practical window runs May 3–May 24, and the 7-day mean crosses the 61°F threshold around May 24. Cold-water starts are the cheap ones.

Full opening guide

Closing — deadline October 1

Hold the cover until September 21, then winterize by October 1, a week ahead of the October 8 freeze normal. Late and cold beats early and warm.

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 Springfield water runs about 25°F at its winter floor and 73°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 Springfield'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.

10°20°30°40°50°60°70°80°JanFebMarAprMayJunJulAugSepOctNovDec65° algae zone58° swimmable startopen May 10close Oct 173°F peak25°F floor
Site-model seasonal water estimates for an unheated in-ground pool near Westfield Barnes Municipal Airport — ±5°F, see methodology.
JanFebMarAprMayJunJulAugSepOctNovDec
27°26°32°42°54°64°71°72°68°57°45°35°

The curve peaks near 73°F — comfortable-water months here usually involve a heater or a solar cover.

Every station tells its own story: compare this curve with Somerville's pool season and Worcester's — neighboring normals stations can shift the windows by a week or more. The full ranking lives on the Massachusetts season index.

Springfield pool season FAQ

When should I open my pool in Springfield, MA?

Open by May 10 — the model places Springfield's 61°F crossing about two weeks later, and every warm day you wait pushes the water toward the 65°F algae zone. The Springfield opening guide has the 12-step sequence.

When should I close my pool in Springfield?

Close by October 1: cool water keeps its winter chemistry, but freeze damage is the hard stop. The Springfield closing guide sequences the work backward from that date.

How long is the swim season in Springfield?

Springfield averages 78 days a year with normal highs of 80°F or better — right on the statewide median. The Massachusetts season index ranks all 14 covered cities by the same metric.

How warm does pool water get in Springfield?

An unheated pool near Springfield typically peaks around 73°F in high summer and bottoms out near 25°F in winter, never quite reaching the 78°F comfort line without a heater or solar cover. The month-by-month curve above shows the whole cycle; the methodology page explains the ±5°F error bars.

Data: NOAA 1991–2020 climate normals via Westfield Barnes Municipal Airport (9.5 mi); live outlook by Open-Meteo. Attribution: sources · assumptions: methodology.