PoolWindow

Pool season · South Carolina

Mount Pleasant Pool Season: the Year on One Bar

Last updated: July 25, 2026 · dates · water temp

Mount Pleasant'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.

Resort pool at dusk in a hot, long-season climateMount Pleasant, SC — 159 swim days a year
J F M A M J J A S O N D today (build date)

off-season opening window swim season closing window

The bar compresses Mount Pleasant's whole pool year into one lane rope: gray floats for the off-season, hollow teal for the March 16–April 6 opening window, solid teal for swim weeks, hollow amber for the closing stretch that ends November 15. Wherever the today marker sits, the nearest color change is your next appointment.

The Mount Pleasant pool calendar

March 23open by
November 15close by
15980°F+ days
82°Fwater peak

Opening — target March 23

Open by March 23 — a two-week head start on the April 6 crossing keeps startup chemistry small and beats the local service rush.

Full opening guide

Closing — deadline November 15

Hold the cover until November 5, then winterize by November 15, a week ahead of the November 30 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 Mount Pleasant water runs about 48°F at its winter floor and 82°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 Mount Pleasant's own normals — the shape of a typical year, not a forecast. The widget above shows where the current year actually sits.

40°50°60°70°80°90°JanFebMarAprMayJunJulAugSepOctNovDec65° algae zone58° swimmable startopen Mar 23close Nov 1582°F peak48°F floor
Site-model seasonal water estimates for an unheated in-ground pool near Sullivans Island — ±5°F, see methodology.
JanFebMarAprMayJunJulAugSepOctNovDec
49°49°53°60°69°76°81°82°79°73°62°54°

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 Mauldin's pool season and Myrtle Beach's — neighboring normals stations can shift the windows by a week or more. The full ranking lives on the South Carolina season index.

Mount Pleasant pool season FAQ

When should I open my pool in Mount Pleasant, SC?

Open by March 23 — the model places Mount Pleasant's 61°F crossing about two weeks later, and every warm day you wait pushes the water toward the 65°F algae zone. The Mount Pleasant opening guide has the 12-step sequence.

When should I close my pool in Mount Pleasant?

Close by November 15: cool water keeps its winter chemistry, but freeze damage is the hard stop. The Mount Pleasant closing guide sequences the work backward from that date.

How long is the swim season in Mount Pleasant?

Mount Pleasant averages 159 days a year with normal highs of 80°F or better — about 5 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 Mount Pleasant?

An unheated pool near Mount Pleasant typically peaks around 82°F in high summer and bottoms out near 48°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.

Data: NOAA 1991–2020 climate normals via Sullivans Island (6.7 mi); live outlook by Open-Meteo. Attribution: sources · assumptions: methodology.