Pool season · State index
South Carolina Pool Season Calendar
Last updated: July 15, 2026 · 12 cities covered
Both halves of the pool year for all 12 covered South Carolina cities. The median calendar runs March 26 to November 4. Every row links to a one-page season overview with the live water-temperature model; the opening and closing hubs carry the full checklists.
| City | Open by | Close by | 80°F+ days |
|---|---|---|---|
| Beaufort | Mar 11 | Nov 17 | 166 |
| Charleston | Mar 13 | Nov 21 | 132 |
| Columbia | Mar 25 | Nov 4 | 159 |
| Florence | Mar 21 | Nov 6 | 160 |
| Greenville | Apr 7 | Oct 22 | 109 |
| Mauldin | Apr 7 | Oct 22 | 109 |
| Mount Pleasant | Mar 23 | Nov 15 | 159 |
| Myrtle Beach | Apr 2 | Nov 5 | 131 |
| North Charleston | Mar 13 | Nov 15 | 164 |
| Rock Hill | Mar 28 | Oct 29 | 142 |
| Spartanburg | Apr 2 | Oct 25 | 142 |
| Sumter | Mar 28 | Oct 30 | 142 |
What the columns mean
"Open by" is the recommended spring date — two weeks before the city's 7-day mean temperature crosses 61°F, the model's proxy for water approaching the 65°F algae-growth zone. "Close by" is the fall deadline — ten days after the water leaves that zone, capped a week ahead of the local 50% first-freeze date. "80°F+ days" counts days whose normal high reaches 80°F: the length of the true warm-swim season, and the fairest single number for comparing South Carolina cities against each other.
Every figure comes from each city's own NOAA 1991–2020 normals station (named in its guide's footer), so neighboring cities can legitimately differ by a few days. The season overview linked from each row adds the live water-temperature model and the full-year season bar; the state hubs above carry the step-by-step checklists.