Decatur weather in August 2025

Expect daytime maximum temperatures of 29°C in Decatur in August based on long-term weather averages. There are 9 hours of sunshine per day on average with typically 93 mm of rainfall in the month.

  • 29°C maximum daytime temperature in August in Decatur29
    29°C max day temperature
  • 9 hours of sunshine per day
  • 8 days with some rainfall in August in Decatur8
    8 days with some rainfall
  • 17°C minimum night-time temperature in August in Decatur17
    17°C min night temperature
  • 14 hours of daylight per day in August in Decatur14
    14 hours of daylight per day
  • Moderate heat & humidity in August in DecaturM
    Moderate heat & humidity
  • 93 mm monthly rainfall in August in Decatur93
    93 mm of monthly rainfall
  • UV (maximum) index 8 (Very High) in August in Decatur8
    8 (Very High) UV index

More about Decatur

Decatur by month

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

Recommended for Illinois

TUI discount code: up to £300 off 2025/2026 holidays

  • Save up to £300 on package holidays in 2025/2026
  • Book in TUI sale. Discount varies by spend. T&Cs apply
  • Travel between 1st May 2025 & 31st Oct 2026 (inclusive)
Show discount codeShow discount code ******ALE
Redeem TUI discount code >>

Expires at 10:00 on Friday 28th Feb 2025 · View all TUI offers

TUITUI deal finder

The August 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)

Back to top

More about the USA

How hot is it in Decatur in August?

Daytime temperatures usually reach 29°C in Decatur in August with moderate heat and humidity, falling to 17°C at night.

How sunny is it in Decatur in August?

There are normally 9 hours of bright sunshine each day in Decatur in August - that's 67% of daylight hours.

Does it rain in Decatur in August?

There are usually 8 days with some rain in Decatur in August and the average monthly rainfall is 93mm.

Decatur August sunrise & sunset times

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

JanFebMarAprMayJunJulAugSepOctNovDec

Date Sunrise times Sunset times
Friday, 1st August 2025 04:55 19:09
Saturday, 16th August 2025 05:09 18:50
Sunday, 31st August 2025 05:23 18:28

Related posts

Popular travel offers

Explore holidays in the sun for less

More holidays

Airport parking

More parking

Airport lounges

More lounges

Top ^