Illinois weather outlook for the next 7 days
From Oct 29 to Nov 4, temperatures in Illinois will range from 51° to 78°. The hottest day is today (Oct 29), with a high of 78°; the coolest night is Wednesday, Nov 4, dipping to around 51°. Overall, daytime temperatures are expected to ease slightly towards the end of the period.
4 of the next 7 days are forecast to bring 0.04 in of rain or more: Sunday, Nov 1 (~0.06 in), Monday, Nov 2 (~0.04 in), Tuesday, Nov 3 (~0.32 in) and Wednesday, Nov 4 (~0.34 in). The wettest day is Wednesday, Nov 4, with around 0.34 in of rain.
The windiest day is Wednesday, Nov 4, with average speeds of about 22 mph and gusts of up to 40 mph. The UV index peaks at 3.6 (moderate) tomorrow (Oct 30). Average daily humidity ranges from 49% to 89%.
- Rainy days ahead: carry an umbrella or raincoat, slow down on wet roads and never drive through flooded roads – turn around, don't drown.
- Strong winds: secure outdoor furniture and trash cans, watch for falling branches and downed power lines, and drivers of high-profile vehicles should use caution.
Frequently asked questions about the weather in Illinois
Will it rain in Illinois in the next 24 hours?
The chance of rain in Illinois over the next 24 hours is low, peaking at only about 0% at 6:00 AM. It should be fine for outdoor plans.
What is the weather in Illinois tomorrow?
Tomorrow (Friday, Oct 30), Illinois will see overcast clouds, with temperatures from 58° to 74°, a 7% chance of rain, humidity around 56% and winds of 9 mph. Cool weather, bring a jacket.
Which day will be hottest in Illinois this week?
According to the forecast, today (Oct 29) will be the hottest day, with a high of about 78°. The coolest is Wednesday, Nov 4, with a low of about 51°.
Which day is best for going out or outdoor activities in Illinois?
Today (Oct 29) is the best day of the next 7: broken clouds, 60° to 78°, with a 0% chance of rain. Go in the morning or late afternoon to avoid the strongest sun.
Is this forecast accurate for every part of Illinois?
The forecast is calculated for a representative point in Illinois. In mountain and coastal areas, or during showers and thunderstorms, conditions can vary a lot from place to place. For tornadoes, hurricanes, floods and winter storms, always follow the official National Weather Service warnings.
Day by day in Illinois
| Day | Weather | High / Low | Rain | Wind | Heat index / wind chill |
|---|---|---|---|---|---|
| Today |  Broken clouds |
78° / 60° | 0% · 0 in | 10 mph | 78° · Not hazardous |
| Tomorrow | Overcast clouds |
74° / 58° | 7% · 0 in | 9 mph | 74° · Not hazardous |
| Sat, Oct 31 | Overcast clouds |
67° / 59° | 45% · 0 in | 8 mph | 65° · Not hazardous |
| Sun, Nov 1 |  Light rain |
66° / 58° | 89% · 0.06 in | 10 mph | 65° · Not hazardous |
| Mon, Nov 2 | Light rain |
64° / 56° | 93% · 0.04 in | 14 mph | 64° · Not hazardous |
| Tue, Nov 3 | Moderate rain |
73° / 63° | 100% · 0.32 in | 20 mph | 74° · Not hazardous |
| Wed, Nov 4 | Moderate rain |
70° / 51° | 100% · 0.34 in | 22 mph | 71° · Not hazardous |
About the heat index and wind chill
The heat index is how hot it really feels when humidity is combined with the air temperature. The National Weather Service uses these levels: 80–90 °F caution, 90–103 °F extreme caution, 103–124 °F danger and 125 °F or more extreme danger. At "danger" level, heat cramps and heat exhaustion are likely with prolonged activity outdoors — drink water often, rest in the shade or air conditioning and avoid strenuous work in the afternoon.
The wind chill is how cold it feels on exposed skin when wind is combined with cold air (it applies at 50 °F and below). At a wind chill of −18 °F frostbite can develop in 30 minutes, at −35 °F in 10 minutes: cover your skin, wear layers, a hat and gloves.