Pool season · Idaho
Idaho Falls Pool Season: the Year on One Bar
Last updated: July 25, 2026 · dates · water temp
This is the one-page view of Idaho Falls'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.
Idaho Falls, ID — 70 swim days a yearThe bar compresses Idaho Falls's whole pool year into one lane rope: gray floats for the off-season, hollow teal for the May 20–June 10 opening window, solid teal for swim weeks, hollow amber for the closing stretch that ends September 23. Wherever the today marker sits, the nearest color change is your next appointment.
The Idaho Falls pool calendar
Opening — target May 27
Open by May 27 — a two-week head start on the June 10 crossing keeps startup chemistry small and beats the local service rush.
Closing — deadline September 23
The window opens September 13 once water leaves the algae zone; the model deadline is September 23, a week ahead of the October 1 freeze normal.
Estimated water temperature by month
This is Idaho Falls'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 |
|---|---|---|---|---|---|---|---|---|---|---|---|
| 23° | 25° | 34° | 43° | 51° | 59° | 67° | 71° | 65° | 54° | 40° | 28° |
The curve peaks near 72°F — comfortable-water months here usually involve a heater or a solar cover.
Every station tells its own story: compare this curve with Coeur d'Alene's pool season and Meridian's — neighboring normals stations can shift the windows by a week or more. The full ranking lives on the Idaho season index.
Idaho Falls pool season FAQ
When should I open my pool in Idaho Falls, ID?
Open by May 27 — the model places Idaho Falls's 61°F crossing about two weeks later, and every warm day you wait pushes the water toward the 65°F algae zone. The Idaho Falls opening guide has the 12-step sequence.
When should I close my pool in Idaho Falls?
Close by September 23: cool water keeps its winter chemistry, but freeze damage is the hard stop. The Idaho Falls closing guide sequences the work backward from that date.
How long is the swim season in Idaho Falls?
Idaho Falls averages 70 days a year with normal highs of 80°F or better — about 18 days later than the Idaho median. The Idaho season index ranks all 5 covered cities by the same metric.
How warm does pool water get in Idaho Falls?
An unheated pool near Idaho Falls typically peaks around 72°F in high summer and bottoms out near 23°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 Idaho Falls hits the closing window
Data: NOAA 1991–2020 climate normals via Idaho Falls - Kifi (2.2 mi); live outlook by Open-Meteo. Attribution: sources · assumptions: methodology.