Charleston averages 28.3 days a year above 90°F, with August the wettest month at 6.11 in of normal rain. The hottest day on record was 104°F on Jun 2, 1985; the coldest, 10°F on Jan 21, 1985. The single biggest 24-hour rain event recorded was 10.38 in on Jun 11, 1973.
Climate and Average Weather Year Round in Charleston
Year-round temperature
In Charleston, the warmest months are June through September, with average daily highs between 83°F and 88°F. The coldest stretch runs December through February, with highs between 58°F and 61°F and overnight lows reaching 44°F.
Rainfall through the year
Rainfall in Charleston averages 3.7 in per month over the long run. August is the wettest at 6.1 in, while November is the driest at 2.3 in.
Days at 90 °F or hotter
Charleston averages 28.3 days per year at 90 °F or hotter. The hottest year on record saw 71 such days (1998); the coolest just 3 (2003).
Precipitation this year
As of May 29, Charleston has received 5.6 in of precipitation this year — 58% below the long-term normal for this point in the year (13.5 in).