Pool season · Idaho
Nampa Pool Season: the Year on One Bar
Last updated: July 15, 2026 · dates · water temp
This is the one-page view of Nampa'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.
Each dot on the bar is one week of Nampa's typical year, colored by what the model says that week is for: gray weeks are off-season, hollow teal marks the opening window (May 2–May 23), solid teal is swim season, and hollow amber is the closing window ending October 3. The black marker is today — its position against the colors is the entire executive summary.
The Nampa pool calendar
Opening — target May 9
Open by May 9 — a two-week head start on the May 23 crossing keeps startup chemistry small and beats the local service rush.
Closing — deadline October 3
Hold the cover until September 23, then winterize by October 3, a week ahead of the October 13 freeze normal. Late and cold beats early and warm.
Estimated water temperature by month
This is Nampa'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 |
|---|---|---|---|---|---|---|---|---|---|---|---|
| 30° | 34° | 41° | 48° | 55° | 64° | 72° | 76° | 69° | 58° | 45° | 35° |
The curve peaks near 77°F — comfortable-water months here usually involve a heater or a solar cover.
Email me when Nampa hits the closing window
Data: NOAA 1991–2020 climate normals via Nampa Sugar Factory (1.5 mi); live outlook by Open-Meteo. Attribution: sources · assumptions: methodology.