Summerville climate — normals and trends
Summerville (United States) has a humid subtropical climate (Cfa) under the Köppen-Geiger classification. Its mean annual temperature is 18.2 °C and it receives 1,207 mm of precipitation per year.
These figures are normals computed over 86 complete calendar years, from 1940 to 2025, using ERA5 reanalysis data from the Copernicus programme.
The warmest month is July (26.7 °C on average) and the coldest is January (8.9 °C). Rainfall peaks in August.
Summerville averages 23 frost days, 88 hot days (≥ 30 °C) and 136 rainy days per year.
Summerville has warmed by +0.9 °C between 1940 and 2025, or +0.11 °C per decade. This trend is statistically significant.
The hottest day of the period reached 39.4 °C (on 17 August 1954) and the coldest -14.3 °C (on 25 December 1989).
Data from ERA5 reanalysis (Copernicus Climate Change Service), redistributed under a CC-BY 4.0 licence. Normals are recomputed whenever the archive is updated.
Climate normals · ERA5
SummervilleSouth Carolina
- coords
- 33.02°, -80.18°
- period
- 1940–2025 · 86 yrs
Mean daily temperature
18.2°C
Average daily high
23.8°C
Average daily low
13.5°C
Annual rainfall
1,207mm
Sunshine / day
9.5h
Mean relative humidity
74%
Average peak wind
14.7km/h
Seasonal range
17.8°C
Frost days (< 0 °C)
23 d/yr
Hot days (≥ 30 °C)
88 d/yr
Rainy days (≥ 1 mm)
136 d/yr
Annual snowfall
1.6 cm
Average feels-like high
24.9 °C
Average feels-like low
13.2 °C
Average peak gust
34.7 km/h
Tropical nights (≥ 20 °C)
110 d/yr
Solar radiation
16.6 MJ/m²
Has the climate changed?
One stripe per year, 1940 to 2025
+0.9 °C
since 1940
+0.1 °C per decade · r² = 0.18 · p = < 0.001
Trend fitted by linear regression (ordinary least squares) on annual means. A trend is shown only when it is statistically significant (p < 0.05).
A climograph overlays rainfall (bars) and temperature (line): the standard reading in climatology, where you can see at a glance whether the warm season is also the dry one.
Records for the period
Hottest day
39.4 °C
17 August 1954
Coldest day
-14.3 °C
25 December 1989
Wettest day
148 mm
23 December 2019
Windiest day
64.9 km/h
21 September 1989
Strongest gust
154.1 km/h
22 September 1989
Hottest feels-like
45.5 °C
1 August 1999
Coldest feels-like
-19.1 °C
21 January 1985
Snowiest day
22.5 cm
10 February 1973
Sunniest day
13.8 h
19 June 2022
Normals computed over complete calendar years 1940–2025.
A specific year
Pick a year and see how it compares to normal — warmer, drier or more extreme than usual?
Across the whole year
Month by month
| High | vs. normal | Precipitation | vs. normal | |
|---|---|---|---|---|
| Jan | 12.2 °C | -2.5 °C | 48 mm | -32 mm |
| Feb | 19.9 °C | +3.3 °C | 28 mm | -55 mm |
| Mar | 22.4 °C | +2.3 °C | 122 mm | +29 mm |
| Apr | 26.1 °C | +1.9 °C | 48 mm | -24 mm |
| May | 29.3 °C | +1.4 °C | 121 mm | +32 mm |
| Jun | 32.1 °C | +1.4 °C | 150 mm | +15 mm |
| Jul | 32.9 °C | +1.1 °C | 206 mm | +46 mm |
| Aug | 29.7 °C | -1.4 °C | 219 mm | +57 mm |
| Sep | 29.0 °C | +0.3 °C | 79 mm | -40 mm |
| Oct | 23.2 °C | -1.3 °C | 179 mm | +99 mm |
| Nov | 21.5 °C | +1.6 °C | 9 mm | -50 mm |
| Dec | 15.8 °C | -0.1 °C | 62 mm | -13 mm |
The year's extremes
What was the weather like that day?
Your birthday, a wedding, a memorable trip: discover the actual weather for any date since 1940.
Frequently asked questions
What is the climate of Summerville?
Summerville has a humid subtropical climate (Köppen Cfa). Over 1940-2025, the average annual temperature is 18.2 °C and it receives 1,207 mm of precipitation per year.
What is the hottest day ever recorded in Summerville?
The hottest day measured in Summerville between 1940 and 2025 was 17 August 1954, reaching 39.4 °C.
What is the coldest day in Summerville?
The coldest day measured in Summerville between 1940 and 2025 was 25 December 1989, at -14.3 °C.
Does it snow in Summerville?
Yes. Summerville gets on average 1.6 cm of snow per year and has around 23 frost days.
Has the climate of Summerville warmed?
Yes: Summerville warmed by +0.9 °C between 1940 and 2025, a statistically significant trend.
What is the wettest day in Summerville?
The wettest day measured in Summerville between 1940 and 2025 was 23 December 2019, with 148 mm of rain in 24 hours.
What was the windiest day in Summerville?
The windiest day measured in Summerville between 1940 and 2025 was 21 September 1989, with winds reaching 64.9 km/h.
What is the warmest month in Summerville?
The warmest month in Summerville is July (26.7 °C on average); the coldest is January (8.9 °C).
How much does it rain in Summerville?
Summerville receives on average 1,207 mm of precipitation per year, spread over about 136 rainy days.
Is it sunny in Summerville?
Summerville gets on average 9.5 hours of sunshine per day, roughly 3,468 hours per year over 1940-2025.
What is the biggest single-day snowfall in Summerville?
The heaviest 24-hour snowfall measured in Summerville between 1940 and 2025 was 10 February 1973, with 22.5 cm.
Are there tropical nights in Summerville?
Yes: Summerville has on average 110 tropical nights per year (temperature staying above 20 °C), over 1940-2025.
What was the most extreme apparent temperature in Summerville?
In Summerville, between 1940 and 2025, the highest apparent temperature reached 45.5 °C on 1 August 1999, and the lowest was -19.1 °C on 21 January 1985.
Compare Summerville with another city
Pick a second city: its normals will be set against these, indicator by indicator.
Nearby cities
The climate around Summerville