Pool season · Missouri
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.
Springfield, MO — 112 swim days a yearReading it takes ten seconds: 52 dots, one per week. Solid teal is Springfield's swim season; the hollow teal run before it (April 12 to May 3) is when to open; the hollow amber run after is when to close, with October 18 as the deadline; gray is the covered season. Today's marker shows where you stand in that cycle right now.
The Springfield pool calendar
Opening — target April 19
Target April 19; the practical window runs April 12–May 3, and the 7-day mean crosses the 61°F threshold around May 3. Cold-water starts are the cheap ones.
Closing — deadline October 18
Hold the cover until October 8, then winterize by October 18, a week ahead of the October 27 freeze normal. Late and cold beats early and warm.
Estimated water temperature by month
Monthly averages of the site's water model run on Springfield'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 |
|---|---|---|---|---|---|---|---|---|---|---|---|
| 33° | 35° | 42° | 52° | 61° | 71° | 76° | 78° | 74° | 64° | 51° | 41° |
Warmest water typically August–August (peaking near 79°F); heaters and covers shift any month up.
Every station tells its own story: compare this curve with O'Fallon's pool season and St. Louis's — neighboring normals stations can shift the windows by a week or more. The full ranking lives on the Missouri season index.
Springfield pool season FAQ
When should I open my pool in Springfield, MO?
The site model recommends opening by April 19 — about two weeks before Springfield's 7-day mean temperature crosses 61°F, while the water is still too cold for algae. The step-by-step sequence is in the Springfield opening guide.
When should I close my pool in Springfield?
Winterize by October 18. The model holds the deadline a week ahead of Springfield's NOAA 50% first-freeze date, so the plumbing is protected before the first hard night. The full sequence is in the Springfield closing guide.
How long is the swim season in Springfield?
Springfield averages 112 days a year with normal highs of 80°F or better — right on the statewide median. The Missouri season index ranks all 8 covered cities by the same metric.
How warm does pool water get in Springfield?
An unheated pool near Springfield typically peaks around 79°F in high summer and bottoms out near 33°F in winter, spending roughly 1 month at or above the 78°F comfort line most swimmers prefer. The month-by-month curve above shows the whole cycle; the methodology page explains the ±5°F error bars.
Email me when Springfield hits the closing window
Data: NOAA 1991–2020 climate normals via Springfield Wbo (0.6 mi); live outlook by Open-Meteo. Attribution: sources · assumptions: methodology.