Pool season · Pennsylvania
York Pool Season: the Year on One Bar
Last updated: July 25, 2026 · dates · water temp
York'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.
York, PA — 107 swim days a yearThe bar compresses York's whole pool year into one lane rope: gray floats for the off-season, hollow teal for the April 17–May 8 opening window, solid teal for swim weeks, hollow amber for the closing stretch that ends October 11. Wherever the today marker sits, the nearest color change is your next appointment.
The York pool calendar
Opening — target April 24
Open by April 24 — a two-week head start on the May 8 crossing keeps startup chemistry small and beats the local service rush.
Closing — deadline October 11
The window opens October 1 once water leaves the algae zone; the model deadline is October 11, a week ahead of the October 19 freeze normal.
Estimated water temperature by month
Monthly averages of the site's water model run on York'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° | 32° | 38° | 48° | 59° | 68° | 74° | 75° | 71° | 61° | 50° | 39° |
The curve peaks near 75°F — comfortable-water months here usually involve a heater or a solar cover.
Every station tells its own story: compare this curve with State College's pool season and Allentown's — neighboring normals stations can shift the windows by a week or more. The full ranking lives on the Pennsylvania season index.
York pool season FAQ
When should I open my pool in York, PA?
The site model recommends opening by April 24 — about two weeks before York'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 York opening guide.
When should I close my pool in York?
Winterize by October 11. The model holds the deadline a week ahead of York's NOAA 50% first-freeze date, so the plumbing is protected before the first hard night. The full sequence is in the York closing guide.
How long is the swim season in York?
York averages 107 days a year with normal highs of 80°F or better — about 5 days earlier than the Pennsylvania median. The Pennsylvania season index ranks all 12 covered cities by the same metric.
How warm does pool water get in York?
An unheated pool near York typically peaks around 75°F in high summer and bottoms out near 31°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.
Email me when York hits the closing window
Data: NOAA 1991–2020 climate normals via York 3 SSW Pump Station (3.5 mi); live outlook by Open-Meteo. Attribution: sources · assumptions: methodology.