Pool season · Idaho
Meridian Pool Season: the Year on One Bar
Last updated: July 25, 2026 · dates · water temp
This is the one-page view of Meridian's pool year: both model windows, the estimated water-temperature curve, and today's live position on the season bar. The detailed checklists live on the opening and closing guides; this page is the calendar you check between them.
Meridian, ID — 96 swim days a yearReading it takes ten seconds: 52 dots, one per week. Solid teal is Meridian's swim season; the hollow teal run before it (April 29 to May 20) is when to open; the hollow amber run after is when to close, with October 9 as the deadline; gray is the covered season. Today's marker shows where you stand in that cycle right now.
The Meridian pool calendar
Opening — target May 6
Target May 6; the practical window runs April 29–May 20, and the 7-day mean crosses the 61°F threshold around May 20. Cold-water starts are the cheap ones.
Closing — deadline October 9
Hold the cover until September 29, then winterize by October 9, a week ahead of the October 21 freeze normal. Late and cold beats early and warm.
Estimated water temperature by month
This is Meridian'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 |
|---|---|---|---|---|---|---|---|---|---|---|---|
| 31° | 34° | 42° | 48° | 56° | 64° | 73° | 78° | 71° | 60° | 46° | 35° |
Warmest water typically August–August (peaking near 79°F); heaters and covers shift any month up.
Every station tells its own story: compare this curve with Idaho Falls's pool season and Nampa's — neighboring normals stations can shift the windows by a week or more. The full ranking lives on the Idaho season index.
Meridian pool season FAQ
When should I open my pool in Meridian, ID?
The site model recommends opening by May 6 — about two weeks before Meridian'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 Meridian opening guide.
When should I close my pool in Meridian?
Winterize by October 9. The model holds the deadline a week ahead of Meridian's NOAA 50% first-freeze date, so the plumbing is protected before the first hard night. The full sequence is in the Meridian closing guide.
How long is the swim season in Meridian?
Meridian averages 96 days a year with normal highs of 80°F or better — right on the statewide median. The Idaho season index ranks all 5 covered cities by the same metric.
How warm does pool water get in Meridian?
An unheated pool near Meridian typically peaks around 79°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 Meridian hits the closing window
Data: NOAA 1991–2020 climate normals via Boise Air Terminal (8.5 mi); live outlook by Open-Meteo. Attribution: sources · assumptions: methodology.