Pool season · South Carolina
Charleston Pool Season: the Year on One Bar
Last updated: July 25, 2026 · dates · water temp
Charleston's whole pool calendar, condensed: when the water warms, when it cools, and where today falls between those edges. Use the opening guide and closing guide for the step-by-step work; keep this page for the dates.
Charleston, SC — 132 swim days a yearReading it takes ten seconds: 52 dots, one per week. Solid teal is Charleston's swim season; the hollow teal run before it (March 6 to March 27) is when to open; the hollow amber run after is when to close, with November 21 as the deadline; gray is the covered season. Today's marker shows where you stand in that cycle right now.
The Charleston pool calendar
Opening — target March 13
Target March 13; the practical window runs March 6–March 27, and the 7-day mean crosses the 61°F threshold around March 27. Cold-water starts are the cheap ones.
Closing — deadline November 21
The window opens November 11 once water leaves the algae zone; the model deadline is November 21, a week ahead of the December 30 freeze normal.
Estimated water temperature by month
Monthly averages of the site's water model run on Charleston's own normals — the shape of a typical year, not a forecast. The widget above shows where the current year actually sits.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|
| 52° | 52° | 56° | 63° | 70° | 77° | 81° | 82° | 80° | 74° | 64° | 57° |
Warmest water typically July–September (peaking near 82°F); heaters and covers shift any month up.
Every station tells its own story: compare this curve with Beaufort's pool season and Columbia's — neighboring normals stations can shift the windows by a week or more. The full ranking lives on the South Carolina season index.
Charleston pool season FAQ
When should I open my pool in Charleston, SC?
The site model recommends opening by March 13 — about two weeks before Charleston'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 Charleston opening guide.
When should I close my pool in Charleston?
Winterize by November 21. The model holds the deadline a week ahead of Charleston's NOAA 50% first-freeze date, so the plumbing is protected before the first hard night. The full sequence is in the Charleston closing guide.
How long is the swim season in Charleston?
Charleston averages 132 days a year with normal highs of 80°F or better — about 15 days earlier than the South Carolina median. The South Carolina season index ranks all 12 covered cities by the same metric.
How warm does pool water get in Charleston?
An unheated pool near Charleston typically peaks around 82°F in high summer and bottoms out near 51°F in winter, spending roughly 3 months at or above the 78°F comfort line most swimmers prefer. The month-by-month curve above shows the whole cycle; the methodology page explains the ±5°F error bars.
Email me when Charleston hits the closing window
Data: NOAA 1991–2020 climate normals via Charleston City (3.3 mi); live outlook by Open-Meteo. Attribution: sources · assumptions: methodology.