Pool season · Colorado
Greeley Pool Season: the Year on One Bar
Last updated: July 25, 2026 · dates · water temp
One bar, one year, one Greeley 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.
Greeley, CO — 115 swim days a yearEach dot on the bar is one week of Greeley's typical year, colored by what the model says that week is for: gray weeks are off-season, hollow teal marks the opening window (April 29–May 20), solid teal is swim season, and hollow amber is the closing window ending October 1. The black marker is today — its position against the colors is the entire executive summary.
The Greeley pool calendar
Opening — target May 6
Open by May 6 — a two-week head start on the May 20 crossing keeps startup chemistry small and beats the local service rush.
Closing — deadline October 1
Hold the cover until September 26, then winterize by October 1, a week ahead of the October 8 freeze normal. Late and cold beats early and warm.
Estimated water temperature by month
This is Greeley'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° | 32° | 39° | 48° | 55° | 66° | 74° | 75° | 70° | 59° | 46° | 34° |
The curve peaks near 76°F — comfortable-water months here usually involve a heater or a solar cover.
Every station tells its own story: compare this curve with Grand Junction's pool season and Highlands Ranch's — neighboring normals stations can shift the windows by a week or more. The full ranking lives on the Colorado season index.
Greeley pool season FAQ
When should I open my pool in Greeley, CO?
Open by May 6 — the model places Greeley's 61°F crossing about two weeks later, and every warm day you wait pushes the water toward the 65°F algae zone. The Greeley opening guide has the 12-step sequence.
When should I close my pool in Greeley?
Close by October 1: cool water keeps its winter chemistry, but freeze damage is the hard stop. The Greeley closing guide sequences the work backward from that date.
How long is the swim season in Greeley?
Greeley averages 115 days a year with normal highs of 80°F or better — about 7 days earlier than the Colorado median. The Colorado season index ranks all 19 covered cities by the same metric.
How warm does pool water get in Greeley?
An unheated pool near Greeley typically peaks around 76°F in high summer and bottoms out near 30°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 Greeley hits the closing window
Data: NOAA 1991–2020 climate normals via Greeley Unc (3.9 mi); live outlook by Open-Meteo. Attribution: sources · assumptions: methodology.