Sumter, United States experiences average highs of 24°C (75°F) and lows of 14°C (57°F) throughout the year. Rainfall is moderate, averaging about 10 rainy days per month. Sunshine is abundant, averaging about 9 hours per day. Average highs have stayed broadly stable across the available records.
Sumter, United States Weather & Climate 2026
Monthly climate averages for Sumter, United States. Based on 10-year ERA5 reanalysis data.
Climate Overview
Drier season: Feb–Nov 
Wetter season: Jan–Dec At-a-Glance Climate Summary
Live Weather & Air Quality
Key figures
Climate Score
6.6/10
Best: April, May, September, October
UV Index
6
High
Temperature 24°C / 14°C
Feels Like 24°C / 14°C
Rainy Days 10
Rainfall 97 mm
Sunshine 9 h
Humidity 70%
Wind Speed 18 km/h
Dew Point 13°C
Snow Days 1 days
Frost Days 4 days
Hottest Month
32°C
July
Avg Low24°C
Rain17days
Coldest Month
4°C
January
Avg High14°C
Rain10days
Driest Month
6days
October
Avg High25°C
Avg Low15°C
Windiest Month
21 km/h
March (Gusts 42)
Worst Time to Visit
Consider avoiding July, August due to extreme heat, heavy rainfall, oppressive humidity.
Sun Position
Sunrise 06:11
Daylight 14.4h
Sunset 20:35
Live conditions—
Sumter on the map · live conditions
Sumter, United States
- Continent
- Americas
- Country
- United States
- City
- Sumter
- Population
- 40.8K
- Elevation
- 52 m
- Coordinates
- 33.92°, -80.34°
Seasonal Breakdown
Spring
Mar–May
Avg High 24°C
Avg Low 14°C
Rain 9 days/mo
2/3 best months
Summer
Jun–Aug
Avg High 31°C
Avg Low 23°C
Rain 15 days/mo
Autumn
Sep–Nov
Avg High 24°C
Avg Low 15°C
Rain 7 days/mo
2/3 best months
Winter
Dec–Feb
Avg High 15°C
Avg Low 6°C
Rain 9 days/mo
Climate Charts
Based on historical averages (2016–2025)
Monthly Temperatures
HighLowShaded bands show the typical range across the available yearly records.
Line chart showing monthly temperatures. Jan: 14°C / 4°C . Feb: 17°C / 7°C . Mar: 20°C / 10°C . Apr: 24°C / 13°C . May: 28°C / 18°C . Jun: 31°C / 22°C . Jul: 32°C / 24°C . Aug: 31°C / 23°C . Sep: 29°C / 21°C . Oct: 25°C / 15°C . Nov: 19°C / 10°C . Dec: 15°C / 6°C .
Monthly Rainfall
Rainfall
Bar chart showing monthly rainfall. Jan: 89 mm. Feb: 79 mm. Mar: 82 mm. Apr: 88 mm. May: 100 mm. Jun: 100 mm. Jul: 131 mm. Aug: 133 mm. Sep: 118 mm. Oct: 69 mm. Nov: 59 mm. Dec: 110 mm.
Monthly Humidity
Humidity
Line chart showing monthly humidity. Jan: 69%. Feb: 70%. Mar: 64%. Apr: 63%. May: 67%. Jun: 71%. Jul: 75%. Aug: 77%. Sep: 72%. Oct: 70%. Nov: 67%. Dec: 72%.
Monthly Wind Speed
Wind SpeedGusts
Bar chart showing monthly wind speed. Jan: 19 km/h . Feb: 20 km/h . Mar: 21 km/h . Apr: 20 km/h . May: 18 km/h . Jun: 16 km/h . Jul: 15 km/h . Aug: 15 km/h . Sep: 16 km/h . Oct: 16 km/h . Nov: 17 km/h . Dec: 18 km/h .
Sunshine
Sunshine
Sunshine: Jan: 7h. Feb: 7h. Mar: 8h. Apr: 10h. May: 10h. Jun: 12h. Jul: 12h. Aug: 10h. Sep: 10h. Oct: 9h. Nov: 8h. Dec: 6h.
UV Index
UV Index
Bar chart showing monthly UV index. Jan: UV 4. Feb: UV 4. Mar: UV 6. Apr: UV 7. May: UV 7. Jun: UV 8. Jul: UV 8. Aug: UV 7. Sep: UV 7. Oct: UV 5. Nov: UV 4. Dec: UV 3.
Monthly Daylight Hours
Daylight12h reference
Monthly Dew Point & Comfort
Dew Point Dry Comfortable Humid Muggy Oppressive
Snow Days
Snow DaysSnowfall
Snow Days: Jan: 1 days. Feb: 0 days. Mar: 0 days. Apr: 0 days. May: 0 days. Jun: 0 days. Jul: 0 days. Aug: 0 days. Sep: 0 days. Oct: 0 days. Nov: 0 days. Dec: 0 days.
Climate Trends
Average highs have stayed broadly stable across the available records. Average rainfall is trending drier by about 22 mm.
2016 to 2025
Avg high Avg rainfall
Climate summary
| Last 12 months | All years | |
|---|---|---|
| Hottest month | Jul 2025 · 34°C | Jul · 32°C |
| Coldest month | Jan 2025 · 0°C | Jan · 4°C |
| Wettest month | Oct 2025 · 177 mm | Aug · 133 mm |
| Windiest month | Mar 2025 · 23 km/h | Mar · 21 km/h |
Month-by-Month Weather Table
January
Fair 
February
Fair March
Good April best
Excellent May best
Excellent June
Fair July
Poor August
Fair September best
Excellent October best
Excellent November
Good December
Fair | Month | Temp | Feels Like | Rain | Sun | Humidity | UV | Status | Details |
|---|---|---|---|---|---|---|---|---|
| January | 14°C / 4°C | 11°C / 1°C | 10days (89 mm) Wet | 6.8h Fair | 69% Muggy | 3.6 Moderate | Fair | View Details |
| February | 17°C / 7°C | 15°C / 4°C | 8days (79 mm) Wet | 7h Good | 70% Muggy | 4.3 Moderate | Fair | View Details |
| March | 20°C / 10°C | 19°C / 7°C | 9days (82 mm) Wet | 8.4h Good | 64% Muggy | 5.8 High | Good | View Details |
| April best | 24°C / 13°C | 24°C / 12°C | 8days (88 mm) Wet | 10.3h Excellent | 63% Muggy | 7.2 Very High | Excellent | View Details |
| May best | 28°C / 18°C | 29°C / 18°C | 10days (100 mm) Wet | 10.4h Excellent | 67% Muggy | 7.2 Very High | Excellent | View Details |
| June | 31°C / 22°C | 34°C / 24°C | 13days (100 mm) Wet | 11.5h Excellent | 71% Muggy | 8 Very High | Fair | View Details |
| July | 32°C / 24°C | 37°C / 28°C | 17days (131 mm) Wet | 11.5h Excellent | 75% Muggy | 8 Very High | Poor | View Details |
| August | 31°C / 23°C | 35°C / 27°C | 16days (133 mm) Wet | 10.3h Excellent | 77% Humid | 7.3 Very High | Fair | View Details |
| September best | 29°C / 21°C | 32°C / 22°C | 9days (118 mm) Wet | 9.8h Good | 72% Muggy | 6.5 High | Excellent | View Details |
| October best | 25°C / 15°C | 25°C / 15°C | 6days (69 mm) Good | 8.6h Good | 70% Muggy | 5.1 High | Excellent | View Details |
| November | 19°C / 10°C | 18°C / 7°C | 7days (59 mm) Good | 7.6h Good | 67% Muggy | 3.9 Moderate | Good | View Details |
| December | 15°C / 6°C | 13°C / 3°C | 10days (110 mm) Wet | 6.3h Fair | 72% Muggy | 3.1 Moderate | Fair | View Details |
Compare Nearby City Climates
Frequently Asked Questions
The best months to visit Sumter are April, May, September, October, when temperatures are comfortable and rainfall is at its lowest. This is based on 10-year climate averages for Sumter, scoring temperature, rainfall, humidity, and sunshine hours.
The hottest month in Sumter is July, with average daytime highs of 32°C (90°F). Plan outdoor activities for early morning or late afternoon if visiting during this period.
The coldest month in Sumter is January, with average overnight lows of 4°C (40°F). Pack warm layers and expect shorter daylight hours during this period.
The wettest month in Sumter is August, averaging 133mm of precipitation across 16 rainy days. An umbrella or waterproof jacket is essential.
The rainy season in Sumter runs through July, August, June, January, with the heaviest rainfall in July. Based on 10-year averages for Sumter.
Sumter receives approximately 108 sunshine hours per year. The sunniest month is June with around 12 hours. Based on climate data for Sumter.
The least favorable months to visit Sumter are July, August, primarily due to extreme heat, heavy rainfall, oppressive humidity. For the best conditions, consider April, May, September, October instead.
The annual average UV index in Sumter is 6, classified as high. Standard sun protection (sunscreen, hat) is recommended during prolonged outdoor exposure.
Average humidity in Sumter is 70%, classified as moderate. Humidity levels are generally comfortable and should not affect outdoor activities for most people.
Yes, Sumter receives snow. Months with snowfall average 1 snow days and 1 cm (0 in) of accumulation, with about 4 frost days during winter.
Average wind speeds in Sumter are 18 km/h (11 mph). The windiest month is March with peak winds reaching 21 km/h (13 mph) (gusts up to 42 km/h / 26 mph).
Sumter averages 6 clear-sky days per month with overall cloud cover around 54%. The clearest skies occur in October.
The annual average dew point in Sumter is 13°C (55°F), which feels pleasant with low humidity. Outdoor activities are comfortable year-round from a humidity standpoint.
Sumter has a Humid Subtropical climate, classified as Cfa under the Köppen system. Temperate climates have mild winters and warm summers, with rainfall spread across the year and four distinct seasons.
The 'feels like' temperature in Sumter ranges from 14°C (57°F) to 24°C (75°F) on average. The 'feels like' temperature closely matches the actual temperature throughout most of the year.
June is not the best time to visit Sumter, with a climate score of 5/10. Consider visiting during April, May, September, October instead for better conditions.
For June in Sumter, pack Umbrella, Waterproof jacket, Breathable clothing, Sunscreen (SPF 30+), Sun hat. With average highs of 31°C (87°F) and 13 rainy days, these essentials will keep you comfortable.
Data Source
Climate data derived from ERA5 reanalysis (ECMWF), averaged over 2016–2025. Sea surface temperature from marine reanalysis data. Climate scores and seasonal estimates are computed by WorldStats.
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