Decatur weather in May 2025

Expect 24°C daytime maximum temperatures in the shade with on average 9 hours of sunshine per day in Decatur in May. Check more long-term weather averages for Decatur in May before you book your next holiday to Illinois in 2025/2026.

  • 24°C maximum daytime temperature in May in Decatur24
    24°C max day temperature
  • 9 hours of sunshine per day
  • 10 days with some rainfall in May in Decatur10
    10 days with some rainfall
  • 11°C minimum night-time temperature in May in Decatur11
    11°C min night temperature
  • 14 hours of daylight per day in May in Decatur14
    14 hours of daylight per day
  • No heat & humidity in May in Decatur0
    No heat & humidity
  • 102 mm monthly rainfall in May in Decatur102
    102 mm of monthly rainfall
  • UV (maximum) index 8 (Very High) in May in Decatur8
    8 (Very High) UV index

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The May 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 / mm)  |  Imperial (°F / inches)

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How hot is it in Decatur in May?

Daytime temperatures usually reach 24°C in Decatur in May, falling to 11°C at night.

How sunny is it in Decatur in May?

There are normally 9 hours of bright sunshine each day in Decatur in May - that's 62% of daylight hours.

Does it rain in Decatur in May?

There are usually 10 days with some rain in Decatur in May and the average monthly rainfall is 102mm.

Decatur May sunrise & sunset times

Browse the sunrise and sunset times for Decatur in May 2025. Select a month to view Decatur sunrise and sunset times for the next 12 months.

JanFebMarAprMayJunJulAugSepOctNovDec

Date Sunrise times Sunset times
Thursday, 1st May 2025 04:56 18:51
Friday, 16th May 2025 04:40 19:05
Saturday, 31st May 2025 04:30 19:18

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