Pool season · Tennessee
Morristown Pool Season: the Year on One Bar
Last updated: July 25, 2026 · dates · water temp
This is the one-page view of Morristown'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.
Morristown, TN — 111 swim days a yearEach dot on the bar is one week of Morristown'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 8–April 29), solid teal is swim season, and hollow amber is the closing window ending October 19. The black marker is today — its position against the colors is the entire executive summary.
The Morristown pool calendar
Opening — target April 15
Target April 15; the practical window runs April 8–April 29, and the 7-day mean crosses the 61°F threshold around April 29. Cold-water starts are the cheap ones.
Closing — deadline October 19
The window opens October 9 once water leaves the algae zone; the model deadline is October 19, a week ahead of the October 28 freeze normal.
Estimated water temperature by month
This is Morristown'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 |
|---|---|---|---|---|---|---|---|---|---|---|---|
| 38° | 38° | 44° | 53° | 62° | 70° | 76° | 76° | 73° | 64° | 52° | 43° |
The curve peaks near 77°F — comfortable-water months here usually involve a heater or a solar cover.
Every station tells its own story: compare this curve with Memphis's pool season and Murfreesboro's — neighboring normals stations can shift the windows by a week or more. The full ranking lives on the Tennessee season index.
Morristown pool season FAQ
When should I open my pool in Morristown, TN?
The site model recommends opening by April 15 — about two weeks before Morristown'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 Morristown opening guide.
When should I close my pool in Morristown?
Winterize by October 19. The model holds the deadline a week ahead of Morristown's NOAA 50% first-freeze date, so the plumbing is protected before the first hard night. The full sequence is in the Morristown closing guide.
How long is the swim season in Morristown?
Morristown averages 111 days a year with normal highs of 80°F or better — about 6 days later than the Tennessee median. The Tennessee season index ranks all 14 covered cities by the same metric.
How warm does pool water get in Morristown?
An unheated pool near Morristown typically peaks around 77°F in high summer and bottoms out near 37°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 Morristown hits the closing window
Data: NOAA 1991–2020 climate normals via Morristown Radio Wcrk (1.8 mi); live outlook by Open-Meteo. Attribution: sources · assumptions: methodology.