Illinois, United States Weather

  1. Illinois, United States Weather
  2. Current conditions
  3. Weather forecast
  4. Averages and extremes
  5. Yesterday's Data
  6. Temperature and possibility of rain in Illinois over the next 12 hours
  7. Temperature and possibility of rain in Illinois in the coming days
  8. Rainfall in Illinois in the coming days
  9. Illinois Weather Summary
  10. Weather averages by month
  11. Illinois's weather
  12. Frequently asked questions
  13. Comments
Illinois, Weather
(Photo by Anthony Fomin on Unsplash)

Current conditions

Updated:
19°C
66.2°F
°C °F

Condition: Drizzle

Pressure: 979 hPa

Feel like: 16 °C

Temperature: 19°C

Cloud: 100%

Humidity: 88%

Wind: S - 33 km/h

Visibility: 14.3 km

Weather forecast

Wed
04 Nov
7°C / 17°C
Moderate Rain
Thu
05 Nov
6°C / 11°C
Drizzle
Fri
06 Nov
2°C / 8°C
Overcast
Sat
07 Nov
0°C / 10°C
Overcast
Sun
08 Nov
1°C / 13°C
Clear Sky
Hourly forecast today:
20:00 PM
17° / 19°
17° / 19°
Drizzle
88% 65 km/h
21:00 PM
17° / 18°
17° / 18°
Overcast
89% 69 km/h
22:00 PM
17° / 18°
17° / 18°
Mainly Clear
90% 66 km/h
23:00 PM
17° / 18°
17° / 18°
Moderate Drizzle
93% 56 km/h
00:00 AM
16° / 18°
16° / 18°
Overcast
88% 42 km/h
01:00 AM
16° / 18°
16° / 18°
Overcast
89% 50 km/h
02:00 AM
16° / 18°
16° / 18°
Overcast
92% 63 km/h
03:00 AM
17° / 18°
17° / 18°
Heavy Rain
95% 44 km/h
04:00 AM
16° / 18°
16° / 18°
Moderate Drizzle
92% 70 km/h
05:00 AM
16° / 17°
16° / 17°
Moderate Drizzle
93% 72 km/h
06:00 AM
16° / 17°
16° / 17°
Moderate Rain
95% 52 km/h

30 Day Averages and Extremes

  • Average high 16.73°C
  • Average low 6.2°C
  • Hottest day 25°C (28 October 2026)
  • Coldest day 0°C (07 November 2026)
  • Average humidity 63.13%
  • Days with precipitation 15 days
  • Highest precipitation 26 mm (03 November 2026)

Yesterday's Data

  • Max: 17°C
  • Min: 12°C
  • Total Precipitation: 0 mm

Temperature and possibility of rain in Illinois over the next 12 hours

Temperature and possibility of rain in Illinois in the coming days

Rainfall in Illinois in the coming days

Illinois Climate Summary

Illinois features a Humid continental, no dry season, hot summer (Köppen classification: Dfa), with an average annual temperature of 12.07ºC (53.73ºF), which is about -0.57% lower than the national average for United States. Annually, the city experiences approximately 38.16 millimeters (1.5 inches) of rainfall, spread across 87.73 rainy days, accounting for 24.04% of the year.

Longitude 40.6331249
Latitude -89.3985283
Yearly high temperature 15.14ºC (59.25ºF)
Yearly low temperature 6.9ºC (44.42ºF)
Hottest month July 27.72ºC (81.9ºF)
Coldest month January -7.09ºC (19.24ºF)
Yearly precip 38.16mm (1.5in)
Days with rainfall 87.73 days (24.04%)
Driest month December (78.37%)
Wettest month May (77.38%)

Weather averages by month

Month High / Low (°C) Rain
January -1.0° / -7.09° 3.82 days
February 1.4° / -5.63° 4.73 days
March 9.03° / 1.17° 6.45 days
April 15.53° / 6.66° 9.0 days
May 22.0° / 13.0° 12.64 days
June 26.49° / 17.26° 10.55 days
July 27.72° / 18.69° 10.91 days
August 27.14° / 17.47° 7.73 days
September 24.45° / 14.28° 7.09 days
October 17.23° / 8.28° 6.36 days
November 8.89° / 1.57° 4.45 days
December 2.76° / -2.82° 4.0 days

Illinois's weather

Frequently asked questions

1. What is the hottest month in Illinois?

July has the highest average monthly temperature (daily mean of 27.72ºC) and January are the coolest (daily mean of -7.09ºC).

2. What should I wear in Illinois today?

For today's mild weather in Illinois, with temperatures between 16ºC to 19ºC (60.8ºF to 66.2ºF), consider wearing:
- Lightweight sweater or cardigan
- Light jacket (for cooler periods)
- Long-sleeve shirt or blouse
- Sun hat (if spending time outdoors)

Temperature

Early
16°C / 17°C
Morning
16°C / 18°C
Afternoon
15°C / 19°C
Evening
17°C / 18°C

Air quality

Good

Satisfactory air quality, minimal pollution, low risk

  • CO2 450
  • CO 132
  • NH3 0
  • NO2 1
  • O3 77
  • PM10 9
  • PM25 6
  • SO2 0
  • CH4 1,380

Sunrise / Sunset

12:30
22:51