Decatur weather in June 2026

Q: How hot is it in Decatur in June?

Daytime temperatures usually reach 27°C in Decatur in June with low heat and humidity, falling to 14°C at night.

Q: How sunny is it in Decatur in June?

There are normally 10 hours of bright sunshine each day in Decatur in June - that's 68% of daylight hours.

Q: How warm is the sea around Decatur in June?

The average sea temperature around Decatur in June is 12°C.

Q: Does it rain in Decatur in June?

There are usually 10 days with some rain in Decatur in June and the average monthly rainfall is 96mm.

Expect daytime maximum temperatures of 84°F in Decatur, Illinois in June based on long-term weather averages. There are 10 hours of sunshine per day on average with typically 3.9 inches of rainfall in the month.

84
84°F max day temperature
10
10 hours of sunshine per day
9
9 days with some rainfall
61
61°F min night temperature
15
15 hours of daylight per day
M
Moderate heat & humidity
3.9
3.9 inches of monthly rainfall
9
9 (Very High) UV index

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The June weather guide for Illinois (Decatur) shows long term weather averages processed from data supplied by CRU (University of East Anglia), the Met Office & the Netherlands Meteorological Institute. Find out more about our data sources.

Metric (°C) | Imperial (°F)