James Island, SC climate
James Island has warm winters and warm summers, with plenty of rain. A typical July afternoon reaches 90°, a January night drops to 41°, and snow is almost unheard of.
NOAA 1991-2020 climate normals Updated once a decadeWhat a year in James Island feels like
Winter
Spring
Summer
Fall
James Island weather by month
Average highs, lows, rain and snow for every month, from NOAA’s 1991–2020 normals.
| Month | High | Low | Rain + melt | Snow | Wet days | Snow on ground | 30-yr range |
|---|---|---|---|---|---|---|---|
| January | 59° | 41° | 3.3" | 0.2" | 9 | 0 | 45° – 56° |
| February | 62° | 44° | 3.1" | 0.1" | 9 | 0 | 45° – 60° |
| March | 68° | 50° | 3.4" | 0 | 8 | 0 | 53° – 66° |
| April | 75° | 57° | 3.3" | 0 | 8 | 0 | 61° – 70° |
| May | 81° | 65° | 3.1" | 0 | 8 | 0 | 70° – 77° |
| June | 87° | 72° | 5.4" | 0 | 12 | 0 | 75° – 83° |
| July | 90° | 75° | 5.7" | 0 | 13 | 0 | 81° – 85° |
| August | 89° | 75° | 6.4" | 0 | 13 | 0 | 79° – 84° |
| September | 85° | 70° | 5.4" | 0 | 10 | 0 | 75° – 82° |
| October | 77° | 60° | 4.4" | 0 | 7 | 0 | 66° – 73° |
| November | 69° | 50° | 2.8" | 0 | 7 | 0 | 55° – 66° |
| December | 62° | 44° | 3.2" | 0 | 9 | 0 | 44° – 63° |
| Year | 75° | 58° | 49.3" | 0.3" | 114 | 0 |
“Wet days” have at least 0.01" of rain or melted snow. “Snow on ground” counts days with 1" or more. The 30-year range is the coldest and warmest that month’s average temperature got between 1991 and 2020.
Rain and snow in James Island
James Island gets 49 inches of rain and melted snow a year. August is the wettest month and November the driest. Rain or snow falls on about 114 days a year.
About 321 frost-free days a year
In half of years the last 32° night comes by February 4 and the first one by December 30. That leaves about 321 frost-free days for gardens, longer than 96% of U.S. towns.
Heating and cooling a home in James Island
Engineers use “degree days” to estimate how hard a furnace or air conditioner works. In James Island, 40% of that work is heating and 60% is cooling, so air conditioning is the bigger bill.
Degree days measure how far each day’s average temperature falls below or rises above 65°, added up over a year. Source: NOAA station normals.
James Island and its neighbors
James Island borders 1 town with climate data. January nights across them vary by 1.2°. Charleston has both the coldest January nights (40°) and the hottest July afternoons (90°). James Island’s January low is 41° and its July high 90°.
Temperatures and rain come from NOAA’s 5 km grid, so each town gets its own value.
How James Island compares
Compared with every U.S. town and city on TownTapestry, each counted once.
Warmer than it used to be
The last 30 years in James Island averaged 1.4° warmer than the 1900s. The biggest change is in December (+2.7°). The shift is larger than in 66% of U.S. towns.
Change by month1991–2020 average minus 1901–2000 average, at James Island’s spot on NOAA’s grid
How much a month can swing
A normal is an average, and real years wander around it. December swings the most: between 1991 and 2020 its average temperature ranged from 44° to 63°. July is the most reliable, staying within 4°.
Common questions about James Island’s climate
What is the coldest month in James Island?
January, with a typical high of 59° and a low of 41°.
What is the hottest month in James Island?
July, with a typical high of 90° and a low of 75°. About 25 days a year reach 90°.
How much snow does James Island get?
Almost none. A normal year brings 0.3 inches.
When is the first frost in James Island?
In half of years the first 32° night comes by December 30, and the last spring frost by February 4.
What is the rainiest month in James Island?
August, with 6.4 inches of rain and melted snow. The year totals 49 inches.
Temperatures and rainfall come from NOAA’s gridded climate normals for James Island itself (about a 3-mile square). Snow, frost dates and day counts come from NOAA’s weather station at Charleston Intl Airport, SC (13 mi, snow) and Charleston City, SC (3 mi, frost, heat and degree days). Normals are 30-year averages, not a forecast. Source: NOAA NCEI U.S. Climate Normals, 1991–2020 and 1901–2000.