Sumter, SC climate
Sumter has mild winters and warm summers. A typical July afternoon reaches 91°, a January night drops to 34°, and snow is almost unheard of.
NOAA 1991-2020 climate normals Updated once a decadeWhat a year in Sumter feels like
Winter
Spring
Summer
Fall
Sumter 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 | 57° | 34° | 3.7" | 0.3" | 11 | 0 | 39° – 52° |
| February | 60° | 37° | 3.4" | 0 | 10 | 0 | 41° – 59° |
| March | 68° | 43° | 3.6" | 0 | 9 | 0 | 47° – 62° |
| April | 76° | 50° | 3.2" | 0 | 8 | 0 | 59° – 68° |
| May | 83° | 59° | 3.6" | 0 | 9 | 0 | 66° – 76° |
| June | 88° | 67° | 4.8" | 0 | 12 | 0 | 74° – 82° |
| July | 91° | 71° | 5.3" | 0 | 11 | 0 | 78° – 85° |
| August | 90° | 70° | 5.2" | 0 | 11 | 0 | 76° – 84° |
| September | 85° | 64° | 4.2" | 0 | 9 | 0 | 72° – 79° |
| October | 76° | 52° | 3.5" | 0 | 8 | 0 | 61° – 69° |
| November | 66° | 42° | 2.8" | 0 | 8 | 0 | 48° – 60° |
| December | 59° | 37° | 3.7" | 0 | 11 | 0 | 39° – 59° |
| Year | 75° | 52° | 46.9" | 0.3" | 117 | 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 Sumter
Sumter gets 47 inches of rain and melted snow a year. July is the wettest month and November the driest. Rain or snow falls on about 117 days a year.
About 230 frost-free days a year
In half of years the last 32° night comes by March 24 and the first one by November 7. That leaves about 230 frost-free days for gardens, longer than 86% of U.S. towns.
Heating and cooling a home in Sumter
Engineers use “degree days” to estimate how hard a furnace or air conditioner works. In Sumter, 61% of that work is heating and 39% is cooling.
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.
Sumter and its neighbors
Sumter borders 7 towns with climate data. January nights across them vary by 0.6°. Mulberry has the coldest January nights (34°) and South Sumter the hottest July afternoons (91°). Sumter’s January low is 34° and its July high 91°.
Temperatures and rain come from NOAA’s 5 km grid, so each town gets its own value.
How Sumter 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 Sumter averaged 0.6° warmer than the 1900s. The biggest change is in December (+1.6°). The shift is smaller than in 93% of U.S. towns.
Change by month1991–2020 average minus 1901–2000 average, at Sumter’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 39° to 59°. July is the most reliable, staying within 7°.
Common questions about Sumter’s climate
What is the coldest month in Sumter?
January, with a typical high of 57° and a low of 34°.
What is the hottest month in Sumter?
July, with a typical high of 91° and a low of 71°. About 58 days a year reach 90°.
How much snow does Sumter get?
Almost none. A normal year brings 0.3 inches.
When is the first frost in Sumter?
In half of years the first 32° night comes by November 7, and the last spring frost by March 24.
What is the rainiest month in Sumter?
July, with 5.3 inches of rain and melted snow. The year totals 47 inches.
Temperatures and rainfall come from NOAA’s gridded climate normals for Sumter itself (about a 3-mile square). Snow, frost dates and day counts come from NOAA’s weather station at Sumter, SC (2 mi) away. Normals are 30-year averages, not a forecast. Source: NOAA NCEI U.S. Climate Normals, 1991–2020 and 1901–2000.