PoolWindow

Pool season · Ohio

Mansfield Pool Season: the Year on One Bar

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

One bar, one year, one Mansfield pool. The season bar below draws everything the model knows — opening window, prime season, closing window — against today's date, with the working details one click away on the opening and closing pages.

Cool blue pool in a short-season northern climateMansfield, OH — 73 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

Reading it takes ten seconds: 52 dots, one per week. Solid teal is Mansfield's swim season; the hollow teal run before it (April 27 to May 18) is when to open; the hollow amber run after is when to close, with October 5 as the deadline; gray is the covered season. Today's marker shows where you stand in that cycle right now.

The Mansfield pool calendar

May 4open by
October 5close by
7380°F+ days
72°Fwater peak

Opening — target May 4

Open by May 4 — a two-week head start on the May 18 crossing keeps startup chemistry small and beats the local service rush.

Full opening guide

Closing — deadline October 5

Hold the cover until September 25, then winterize by October 5, a week ahead of the October 22 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 Mansfield water runs about 26°F at its winter floor and 72°F at its summer peak.

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

Estimated water temperature by month

Monthly averages of the site's water model run on Mansfield's own normals — the shape of a typical year, not a forecast. The widget above shows where the current year actually sits.

20°30°40°50°60°70°80°JanFebMarAprMayJunJulAugSepOctNovDec65° algae zone58° swimmable startopen May 4close Oct 572°F peak26°F floor
Site-model seasonal water estimates for an unheated in-ground pool near Mansfield Lahm Municipal Airport — ±5°F, see methodology.
JanFebMarAprMayJunJulAugSepOctNovDec
28°27°34°44°56°65°72°72°68°59°47°36°

The curve peaks near 72°F — comfortable-water months here usually involve a heater or a solar cover.

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

Mansfield pool season FAQ

When should I open my pool in Mansfield, OH?

The site model recommends opening by May 4 — about two weeks before Mansfield'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 Mansfield opening guide.

When should I close my pool in Mansfield?

Winterize by October 5. The model holds the deadline a week ahead of Mansfield's NOAA 50% first-freeze date, so the plumbing is protected before the first hard night. The full sequence is in the Mansfield closing guide.

How long is the swim season in Mansfield?

Mansfield averages 73 days a year with normal highs of 80°F or better — right on the statewide median. The Ohio season index ranks all 14 covered cities by the same metric.

How warm does pool water get in Mansfield?

An unheated pool near Mansfield typically peaks around 72°F in high summer and bottoms out near 26°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 Mansfield Lahm Municipal Airport (3.8 mi); live outlook by Open-Meteo. Attribution: sources · assumptions: methodology.