Pool season · Tennessee
Johnson City Pool Season: the Year on One Bar
Last updated: July 15, 2026 · dates · water temp
This is the one-page view of Johnson City'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 Johnson City'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 13–May 4), solid teal is swim season, and hollow amber is the closing window ending October 15. The black marker is today — its position against the colors is the entire executive summary.
The Johnson City pool calendar
Opening — target April 20
Target April 20; the practical window runs April 13–May 4, and the 7-day mean crosses the 61°F threshold around May 4. Cold-water starts are the cheap ones.
Closing — deadline October 15
Hold the cover until October 5, then winterize by October 15, a week ahead of the October 24 freeze normal. Late and cold beats early and warm.
Estimated water temperature by month
This is Johnson City'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 |
|---|---|---|---|---|---|---|---|---|---|---|---|
| 37° | 37° | 43° | 51° | 60° | 68° | 74° | 74° | 71° | 63° | 51° | 42° |
The curve peaks near 75°F — comfortable-water months here usually involve a heater or a solar cover.
Email me when Johnson City hits the closing window
Data: NOAA 1991–2020 climate normals via Elizabethton (7.4 mi); live outlook by Open-Meteo. Attribution: sources · assumptions: methodology.