Pool season · South Carolina
Rock Hill Pool Season: the Year on One Bar
Last updated: July 25, 2026 · dates · water temp
This is the one-page view of Rock Hill'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.
Rock Hill, SC — 142 swim days a yearEach dot on the bar is one week of Rock Hill's typical year, colored by what the model says that week is for: gray weeks are off-season, hollow teal marks the opening window (March 21–April 11), solid teal is swim season, and hollow amber is the closing window ending October 29. The black marker is today — its position against the colors is the entire executive summary.
The Rock Hill pool calendar
Opening — target March 28
Target March 28; the practical window runs March 21–April 11, and the 7-day mean crosses the 61°F threshold around April 11. Cold-water starts are the cheap ones.
Closing — deadline October 29
Hold the cover until October 20, then winterize by October 29, a week ahead of the November 5 freeze normal. Late and cold beats early and warm.
Estimated water temperature by month
Monthly averages of the site's water model run on Rock Hill'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 |
|---|---|---|---|---|---|---|---|---|---|---|---|
| 44° | 44° | 50° | 59° | 67° | 74° | 79° | 80° | 77° | 68° | 57° | 48° |
Warmest water typically July–August (peaking near 80°F); heaters and covers shift any month up.
Every station tells its own story: compare this curve with North Charleston's pool season and Spartanburg's — neighboring normals stations can shift the windows by a week or more. The full ranking lives on the South Carolina season index.
Rock Hill pool season FAQ
When should I open my pool in Rock Hill, SC?
Target March 28. That date backs off two weeks from the day Rock Hill's 7-day mean temperature reaches 61°F, so you start up in cold, algae-resistant water. Work the full checklist in the Rock Hill opening guide.
When should I close my pool in Rock Hill?
The closing deadline is October 29 — late enough that the water has cooled out of the algae zone, early enough to beat Rock Hill's first-freeze normal by about a week. See the Rock Hill closing guide for the winterizing steps.
How long is the swim season in Rock Hill?
Rock Hill averages 142 days a year with normal highs of 80°F or better — right on the statewide median. The South Carolina season index ranks all 12 covered cities by the same metric.
How warm does pool water get in Rock Hill?
An unheated pool near Rock Hill typically peaks around 80°F in high summer and bottoms out near 43°F in winter, spending roughly 2 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 Rock Hill hits the closing window
Data: NOAA 1991–2020 climate normals via Winthrop University (0.6 mi); live outlook by Open-Meteo. Attribution: sources · assumptions: methodology.