PoolWindow

Pool season · South Carolina

Rock Hill Pool Season: the Year on One Bar

Last updated: July 15, 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.

J F M A M J J A S O N D today (build date)

off-season opening window swim season closing window

Each 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

March 28open by
October 29close by
14280°F+ days
80°Fwater peak

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.

Full opening guide

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.

Full closing guide

Where the water sits today

SEASONAL VIEW

Estimated unheated pool water temp (site model, ±5°F). The live estimate loads in your browser from Open-Meteo air temperatures; in a typical year Rock Hill water runs about 43°F at its winter floor and 80°F at its summer peak.

40 45 50 55 60 65 70 75 80 85 58 open 65 algae

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.

Site-model seasonal water estimates for an unheated in-ground pool near Winthrop University — ±5°F, see methodology.
JanFebMarAprMayJunJulAugSepOctNovDec
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.

Data: NOAA 1991–2020 climate normals via Winthrop University (0.6 mi); live outlook by Open-Meteo. Attribution: sources · assumptions: methodology.