If you're worried about language barriers, you can buy your tickets in advance. Upon entry, simply have them scan your barcode; you basically don't need to say a word. Aside from the Skydeck, which could only be rescheduled due to weather, everything else was great. I recommend not booking these kinds of sightseeing trips in advance; it's better to decide on the time after you arrive.
Anonymous User
Couple
Best time to visit Illinois
Data source:Meteostat Update date:2025-09
Weather in Illinois throughout the year
Spring (March–May): Average 6.7–19.6°C, gradually warming climate with abundant rainfall, but significant temperature fluctuations. Common activities: Outdoor excursions, flower viewing. Recommended clothing: Layered clothing, jacket, long-sleeved shirts, comfortable shoes.
Summer (June–August): Average 23.9–24.3°C, hot and humid with higher rainfall, occasional thunderstorms. Common activities: Swimming, camping, outdoor BBQ. Recommended clothing: Light and breathable clothing, sun hat, sunglasses.
Autumn (September–November): Average 19.8–6.8°C, gradually decreasing temperatures, pleasant weather, reduced rainfall. Common activities: Maple viewing, hiking, harvesting crops. Recommended clothing: Comfortable long-sleeved shirts, light jacket, warm clothing.
Winter (December–February): Average -1.8–2.0°C, cold and dry, snowfall varies by year. Common activities: Skiing, ice skating, indoor activities. Recommended clothing: Warm clothing, thick jacket, hat, gloves, scarf.
Weather in Illinois
Annual average temperature: approx. 12.6°C / Annual rainfall: approx. 1179 mm / Summer humidity: 60%–75% / Rainiest month: August
Illinois weather by month
Month
Air temperature (°C)
Precipitation (mm)
January
-1.8°C
69.9
February
1.5°C
92.4
March
6.7°C
121.3
April
12.1°C
113.8
May
19.6°C
108
June
23.9°C
114.6
July
24.3°C
151.9
August
23.2°C
163.7
September
19.8°C
53.4
October
13.4°C
61.5
November
6.8°C
80.9
December
2°C
48.4
7-day weather forecast for Illinois
10/26
Monday
Overcast
24.3°C/12.4°C
10/27
Tuesday
Overcast
21.9°C/11.9°C
10/28
Wednesday
Sunny
24.8°C/13.5°C
10/29
Thursday
Sunny
26.1°C/14.8°C
10/30
Friday
Overcast
25.7°C/15°C
10/31
Saturday
Overcast
21.4°C/16.2°C
11/1
Sunday
Patchy rain nearby
21.6°C/15.6°C
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