Eureka, IL Weather & Climate Normals
Eureka's real weather, in one number
Eureka, IL scores 41/100 on this site's reading of NOAA's own 30-year normals: strongly seasonal. Comfortable weather is limited to a shorter window; summers, winters, or precipitation swing wide. 4 of the year's 12 months average between 55 and 75°F, the range this site counts as mild.
Eureka's hottest and coldest months
Eureka's hottest month is Jul, averaging 75°F; its coldest is Jan, averaging 25°F, a 50°F swing across the year, one of the widest gaps in this dataset.
Eureka's weather across the year
| Month | Avg high | Avg low | Precip | Snow |
|---|---|---|---|---|
| Jan | 33°F | 17°F | 2.05in | 6.8in |
| Feb | 38°F | 21°F | 1.76in | 5.2in |
| Mar | 50°F | 31°F | 2.44in | 2.8in |
| Apr | 63°F | 41°F | 3.77in | 0.8in |
| May | 74°F | 52°F | 4.77in | 0in |
| Jun | 83°F | 61°F | 4.05in | 0in |
| Jul | 86°F | 65°F | 3.86in | 0in |
| Aug | 84°F | 63°F | 3.74in | 0in |
| Sep | 80°F | 55°F | 3.21in | 0in |
| Oct | 67°F | 43°F | 3.14in | 0in |
| Nov | 51°F | 32°F | 2.64in | 1.5in |
| Dec | 39°F | 23°F | 2.04in | 5.2in |
May, Jun, Aug, and Sep are the best time to see Eureka at its mildest; the rest of the year, plan around Jul's heat and Jan's cold.
Rain and snow in Eureka
Eureka averages 37.47in of precipitation a year across roughly 110 days with measurable rain or snow, and 22.3in of snow a year.
Where Eureka ranks
Eureka ranks 4478 of 4876 US cities in this dataset for comfort score, and 291 of 330 within IL. About 5,189 people live there.
If you need tomorrow's forecast, not the 30-year average
Everything above is a 30-year average from Congerville 2nw, IL US, 6.7 miles from Eureka, not a prediction for any specific day.
More on how this is worked out
What a 30-year climate normal actually is · Why this uses the nearest NOAA station