Pool season · Indiana
Anderson Pool Season: the Year on One Bar
Last updated: July 25, 2026 · dates · water temp
Anderson'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.
Anderson, IN — 87 swim days a yearThe bar compresses Anderson's whole pool year into one lane rope: gray floats for the off-season, hollow teal for the April 20–May 11 opening window, solid teal for swim weeks, hollow amber for the closing stretch that ends October 10. Wherever the today marker sits, the nearest color change is your next appointment.
The Anderson 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
Hold the cover until September 30, then winterize by October 10, a week ahead of the October 23 freeze normal. Late and cold beats early and warm.
Estimated water temperature by month
This is Anderson'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.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|
| 29° | 29° | 37° | 48° | 58° | 68° | 74° | 74° | 70° | 61° | 48° | 37° |
The curve peaks near 74°F — comfortable-water months here usually involve a heater or a solar cover.
Every station tells its own story: compare this curve with Terre Haute's pool season and Bloomington's — neighboring normals stations can shift the windows by a week or more. The full ranking lives on the Indiana season index.
Anderson pool season FAQ
When should I open my pool in Anderson, IN?
Target April 27. That date backs off two weeks from the day Anderson's 7-day mean temperature reaches 61°F, so you start up in cold, algae-resistant water. Work the full checklist in the Anderson opening guide.
When should I close my pool in Anderson?
The closing deadline is October 10 — late enough that the water has cooled out of the algae zone, early enough to beat Anderson's first-freeze normal by about a week. See the Anderson closing guide for the winterizing steps.
How long is the swim season in Anderson?
Anderson averages 87 days a year with normal highs of 80°F or better — about 4 days earlier than the Indiana median. The Indiana season index ranks all 13 covered cities by the same metric.
How warm does pool water get in Anderson?
An unheated pool near Anderson typically peaks around 74°F in high summer and bottoms out near 28°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 Anderson hits the closing window
Data: NOAA 1991–2020 climate normals via Anderson Sewage Plt (2.1 mi); live outlook by Open-Meteo. Attribution: sources · assumptions: methodology.