Pool season · California
Riverside Pool Season: the Year on One Bar
Last updated: July 25, 2026 · dates · water temp
One bar, one year, one Riverside 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.
Riverside, CA — 183 swim days a yearReading it takes ten seconds: 52 dots, one per week. Solid teal is Riverside's swim season; the hollow teal run before it (March 5 to March 26) is when to open; the hollow amber run after is when to close, with November 26 as the deadline; gray is the covered season. Today's marker shows where you stand in that cycle right now.
The Riverside pool calendar
Opening — target March 12
Target March 12; the practical window runs March 5–March 26, and the 7-day mean crosses the 61°F threshold around March 26. Cold-water starts are the cheap ones.
Closing — deadline November 26
Hold the cover until November 16, then winterize by November 26, a week ahead of the December 25 freeze normal. Late and cold beats early and warm.
Estimated water temperature by month
Monthly averages of the site's water model run on Riverside'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 |
|---|---|---|---|---|---|---|---|---|---|---|---|
| 56° | 57° | 58° | 62° | 66° | 71° | 78° | 80° | 80° | 73° | 65° | 58° |
Warmest water typically July–September (peaking near 81°F); heaters and covers shift any month up.
Every station tells its own story: compare this curve with Richmond's pool season and Rocklin's — neighboring normals stations can shift the windows by a week or more. The full ranking lives on the California season index.
Riverside pool season FAQ
When should I open my pool in Riverside, CA?
Open by March 12 — the model places Riverside's 61°F crossing about two weeks later, and every warm day you wait pushes the water toward the 65°F algae zone. The Riverside opening guide has the 12-step sequence.
When should I close my pool in Riverside?
Close by November 26: cool water keeps its winter chemistry, but freeze damage is the hard stop. The Riverside closing guide sequences the work backward from that date.
How long is the swim season in Riverside?
Riverside averages 183 days a year with normal highs of 80°F or better — about 20 days earlier than the California median. The California season index ranks all 147 covered cities by the same metric.
How warm does pool water get in Riverside?
An unheated pool near Riverside typically peaks around 81°F in high summer and bottoms out near 55°F in winter, spending roughly 2 months 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 Riverside hits the closing window
Data: NOAA 1991–2020 climate normals via Riverside Fire Station 3 (1.0 mi); live outlook by Open-Meteo. Attribution: sources · assumptions: methodology.