Pool season · Pennsylvania
Reading Pool Season: the Year on One Bar
Last updated: July 25, 2026 · dates · water temp
Reading'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.
Reading, PA — 91 swim days a yearEach dot on the bar is one week of Reading's typical year, colored by what the model says that week is for: gray weeks are off-season, hollow teal marks the opening window (April 20–May 11), solid teal is swim season, and hollow amber is the closing window ending October 10. The black marker is today — its position against the colors is the entire executive summary.
The Reading pool calendar
Opening — target April 27
Open by April 27 — a two-week head start on the May 11 crossing keeps startup chemistry small and beats the local service rush.
Closing — deadline October 10
The window opens September 30 once water leaves the algae zone; the model deadline is October 10, a week ahead of the October 29 freeze normal.
Estimated water temperature by month
Monthly averages of the site's water model run on Reading'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 |
|---|---|---|---|---|---|---|---|---|---|---|---|
| 32° | 31° | 37° | 48° | 58° | 68° | 75° | 76° | 71° | 61° | 49° | 40° |
The curve peaks near 76°F — comfortable-water months here usually involve a heater or a solar cover.
Every station tells its own story: compare this curve with Pittsburgh's pool season and Scranton's — neighboring normals stations can shift the windows by a week or more. The full ranking lives on the Pennsylvania season index.
Reading pool season FAQ
When should I open my pool in Reading, PA?
Target April 27. That date backs off two weeks from the day Reading's 7-day mean temperature reaches 61°F, so you start up in cold, algae-resistant water. Work the full checklist in the Reading opening guide.
When should I close my pool in Reading?
The closing deadline is October 10 — late enough that the water has cooled out of the algae zone, early enough to beat Reading's first-freeze normal by about a week. See the Reading closing guide for the winterizing steps.
How long is the swim season in Reading?
Reading averages 91 days a year with normal highs of 80°F or better — right on the statewide median. The Pennsylvania season index ranks all 12 covered cities by the same metric.
How warm does pool water get in Reading?
An unheated pool near Reading typically peaks around 76°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 Reading hits the closing window
Data: NOAA 1991–2020 climate normals via Reading Spaatz Field (2.8 mi); live outlook by Open-Meteo. Attribution: sources · assumptions: methodology.