DeKalb

Sweetwater County, Illinois, United States

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Current Weather

20°

Overcast

Feels Like: 19°

Min: 17°

Max: 21°

The next few hours will be overcast, with today reaching 21°C and dropping to 17°C. The coming days will be drizzle

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Compare today's weather with yesterday's data and track temperature trends over time.

Hourly Forecast

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11am
12pm
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9pm
10pm
11pm
12am
1am
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Today
Tomorrow

Daylight Hours

06:42

Sunrise

18:55

Sunset

12 hours 13 minutes of sunlight today

Moon

Waxing Crescent

12:42

Moonrise

20:57

Moonset

Daily Forecast

Today

17°
21°

Thursday

17°
23°

Friday

16°
22°

Saturday

18°
26°

Sunday

16°
20°

Monday

15°
19°

Tuesday

13°
19°

Wednesday

13°
21°

Thursday

13°
24°

Friday

13°
23°

Air Quality Data Available

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UV Index

Wear sunscreen
3 Moderate
Low Extreme

Humidity

81% Humid
Low High

Weather in DeKalb today, September 16, 2026

Expect a muted, overcast feel in DeKalb on September 16, 2026 as cloud persists. Brighter breaks, if they arrive, should stay brief. The morning sky stays heavily clouded, with cover near 100% around 10:00. Grey conditions set the early tone before any later change.

Temperatures climb from an overnight low near 17°C toward a daytime high of about 21°C. Relative humidity sits between 78% and 91%, reaching its peak around 13:00. Expect gentle winds, highest near 16:00 at 4.0 km/h.

Afternoon skies stay clogged, peaking close to 100% near 12:00. The grey theme continues rather than clearing out. Visibility holds near 15.3 km, though it can fall to 8.1 km. The sun rises at 06:42 and sets at 18:55, for a total of 12 hours 13 minutes of sunlight today.

Taken together, overcast skies in DeKalb on September 16, 2026 favour indoor or covered options, with temperatures near 21°C.

Frequently asked questions about weather in DeKalb

How warm does it get in DeKalb?

The warmest month in DeKalb is July, with average high temperatures of 28°C. The average temperature during this period is around 24°C.

How cold does it get in DeKalb?

The coldest month in DeKalb is January, with average low temperatures of -8°C. The average temperature during this period is around -5°C.

What is the wettest time of year in DeKalb?

The wettest month in DeKalb is May, with an average of 130mm of precipitation.

What is the driest time of year in DeKalb?

The driest month in DeKalb is February, with an average of 49mm of precipitation.

View full climate insights for DeKalb →

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