Home › Cities › United States › South Carolina › Summerville
Summerville, South Carolina climate
Cfa Humid subtropical
Summerville has a seasonal warm-temperate climate (Humid subtropical, Köppen Cfa). The hottest month is July with an average daily high near 33°C, while the coldest is January averaging around 4°C at night. Around 1334 mm of precipitation falls each year, peaking in August (177 mm) and easing off in November (68 mm).
Temperature & precipitation
Daily high–low temperature range with the monthly average, plus monthly precipitation · 1991–2020 normals · hover a month for the exact figuresClear vs cloudy days
Share of days each month that are clear, partly cloudy or cloudy · 1991–2020 · hover a month for the day countsSummerville climate normals (1991–2020)
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg high (°C) | 16 | 18 | 21 | 25 | 29 | 31 | 33 | 32 | 30 | 26 | 21 | 17 |
| Avg temp (°C) | 10 | 12 | 15 | 19 | 23 | 26 | 28 | 27 | 25 | 20 | 15 | 11 |
| Avg low (°C) | 4 | 5 | 9 | 13 | 17 | 21 | 23 | 23 | 20 | 14 | 8 | 5 |
| Precipitation (mm) | 86 | 77 | 85 | 84 | 84 | 158 | 168 | 177 | 153 | 110 | 68 | 85 |
| Snowfall (cm) | 1 | 0 | — | — | — | — | — | — | — | — | — | — |
| Jan – Jun | Jan | Feb | Mar | Apr | May | Jun |
|---|---|---|---|---|---|---|
| Avg high (°C) | 16 | 18 | 21 | 25 | 29 | 31 |
| Avg temp (°C) | 10 | 12 | 15 | 19 | 23 | 26 |
| Avg low (°C) | 4 | 5 | 9 | 13 | 17 | 21 |
| Precipitation (mm) | 86 | 77 | 85 | 84 | 84 | 158 |
| Snowfall (cm) | 1 | 0 | — | — | — | — |
| Jul – Dec | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|
| Avg high (°C) | 33 | 32 | 30 | 26 | 21 | 17 |
| Avg temp (°C) | 28 | 27 | 25 | 20 | 15 | 11 |
| Avg low (°C) | 23 | 23 | 20 | 14 | 8 | 5 |
| Precipitation (mm) | 168 | 177 | 153 | 110 | 68 | 85 |
| Snowfall (cm) | — | — | — | — | — | — |
How often — frequency of weather events
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Days with measurable rain (days) | 9 | 8 | 8 | 8 | 8 | 12 | 13 | 13 | 10 | 7 | 7 | 9 |
| Days with high ≥ 32°C (days) | — | — | 0.0 | 0.6 | 5 | 14 | 21 | 17 | 6 | 0.5 | — | — |
| Days with low ≤ 0°C (days) | 9 | 4 | 2 | 0.0 | — | — | — | — | — | — | 1 | 6 |
| Days with snowfall ≥ 2.5 cm (days) | 0.1 | 0.0 | — | — | — | — | — | — | — | — | — | — |
| Jan – Jun | Jan | Feb | Mar | Apr | May | Jun |
|---|---|---|---|---|---|---|
| Days with measurable rain (days) | 9 | 8 | 8 | 8 | 8 | 12 |
| Days with high ≥ 32°C (days) | — | — | 0.0 | 0.6 | 5 | 14 |
| Days with low ≤ 0°C (days) | 9 | 4 | 2 | 0.0 | — | — |
| Days with snowfall ≥ 2.5 cm (days) | 0.1 | 0.0 | — | — | — | — |
| Jul – Dec | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|
| Days with measurable rain (days) | 13 | 13 | 10 | 7 | 7 | 9 |
| Days with high ≥ 32°C (days) | 21 | 17 | 6 | 0.5 | — | — |
| Days with low ≤ 0°C (days) | — | — | — | — | 1 | 6 |
| Days with snowfall ≥ 2.5 cm (days) | — | — | — | — | — | — |
Sky & atmosphere
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Cloud cover (%) | 59 | 60 | 54 | 49 | 50 | 55 | 54 | 58 | 55 | 46 | 50 | 58 |
| Clear days (≤ 30% cloud) | 8 | 6 | 9 | 10 | 10 | 7 | 7 | 6 | 8 | 13 | 11 | 8 |
| Partly cloudy days (30–70%) | 10 | 10 | 10 | 11 | 12 | 12 | 14 | 13 | 11 | 8 | 9 | 9 |
| Cloudy days (≥ 70%) | 13 | 12 | 12 | 9 | 10 | 11 | 10 | 12 | 11 | 10 | 10 | 13 |
| Relative humidity (%) | 81 | 81 | 78 | 75 | 73 | 76 | 77 | 79 | 80 | 79 | 79 | 82 |
| Wind speed (m/s) | 1.5 | 1.5 | 1.5 | 1.4 | 1.3 | 1.2 | 1.2 | 1.2 | 1.3 | 1.3 | 1.4 | 1.4 |
| Jan – Jun | Jan | Feb | Mar | Apr | May | Jun |
|---|---|---|---|---|---|---|
| Cloud cover (%) | 59 | 60 | 54 | 49 | 50 | 55 |
| Clear days (≤ 30% cloud) | 8 | 6 | 9 | 10 | 10 | 7 |
| Partly cloudy days (30–70%) | 10 | 10 | 10 | 11 | 12 | 12 |
| Cloudy days (≥ 70%) | 13 | 12 | 12 | 9 | 10 | 11 |
| Relative humidity (%) | 81 | 81 | 78 | 75 | 73 | 76 |
| Wind speed (m/s) | 1.5 | 1.5 | 1.5 | 1.4 | 1.3 | 1.2 |
| Jul – Dec | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|
| Cloud cover (%) | 54 | 58 | 55 | 46 | 50 | 58 |
| Clear days (≤ 30% cloud) | 7 | 6 | 8 | 13 | 11 | 8 |
| Partly cloudy days (30–70%) | 14 | 13 | 11 | 8 | 9 | 9 |
| Cloudy days (≥ 70%) | 10 | 12 | 11 | 10 | 10 | 13 |
| Relative humidity (%) | 77 | 79 | 80 | 79 | 79 | 82 |
| Wind speed (m/s) | 1.2 | 1.2 | 1.3 | 1.3 | 1.4 | 1.4 |
30-year delta table (1991–2020 minus 1981–2010, °F)
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Δ Max temp | +1.2 | +1.0 | +0.5 | +0.7 | +0.4 | +0.1 | +0.2 | +0.3 | +0.6 | +0.8 | -0.4 | +1.1 |
| Δ Avg temp | +1.2 | +1.0 | +0.6 | +1.0 | +0.8 | +0.4 | +0.4 | +0.5 | +0.9 | +0.9 | -0.3 | +1.4 |
| Δ Min temp | +1.4 | +1.0 | +0.6 | +1.2 | +1.2 | +0.8 | +0.7 | +0.8 | +1.1 | +0.9 | -0.4 | +1.5 |
| Jan – Jun | Jan | Feb | Mar | Apr | May | Jun |
|---|---|---|---|---|---|---|
| Δ Max temp | +1.2 | +1.0 | +0.5 | +0.7 | +0.4 | +0.1 |
| Δ Avg temp | +1.2 | +1.0 | +0.6 | +1.0 | +0.8 | +0.4 |
| Δ Min temp | +1.4 | +1.0 | +0.6 | +1.2 | +1.2 | +0.8 |
| Jul – Dec | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|
| Δ Max temp | +0.2 | +0.3 | +0.6 | +0.8 | -0.4 | +1.1 |
| Δ Avg temp | +0.4 | +0.5 | +0.9 | +0.9 | -0.3 | +1.4 |
| Δ Min temp | +0.7 | +0.8 | +1.1 | +0.9 | -0.4 | +1.5 |
Methodology & sources
Temperature & precipitation — the official 1991–2020 climate normals from NOAA's U.S. Climate Normals, measured at Charleston Intl AP (NOAA GHCN station USW00013880), about 18 km from the city centre.
Cloud, humidity, wind & sunshine — modelled estimates from NASA POWER, NASA's satellite-and-reanalysis climatology. This is the standard global source for atmospheric variables, which are not measured at most weather stations.