Illinois 기후 and Average 날씨
기후 of Illinois: average temperatures, rainfall and seasons month by month.
기후 in Illinois month by month
Average high, average low and total rainfall, based on three years of reanalysis data.
| 월 | Avg high | Avg low | 비fall | Rating |
|---|---|---|---|---|
| 1월 | 1° | -7° | 62 mm | ★★☆☆☆ |
| 2월 | 8° | -3° | 20 mm | ★★★☆☆ |
| 3월 | 15° | 4° | 90 mm | ★★★☆☆ |
| 4월 | 19° | 9° | 135 mm | ★★★☆☆ |
| 5월 | 24° | 13° | 100 mm | ★★★★☆ |
| 6월 | 28° | 19° | 117 mm | ★★★★☆ |
| 7월 | 29° | 21° | 129 mm | ★★★★☆ |
| 8월 | 29° | 19° | 75 mm | ★★★★☆ |
| 9월 | 28° | 17° | 33 mm | ★★★★★ |
| 10월 | 20° | 10° | 37 mm | ★★★★☆ |
| 11월 | 12° | 4° | 79 mm | ★★★☆☆ |
| 12월 | 6° | -2° | 62 mm | ★★☆☆☆ |
기후 type: 대륙al. 출처: Open-Meteo archive (ERA5).
Recent extremes in Illinois
높음est and lowest readings observed in the last 3 years of reanalysis data - not all-time records.
How Illinois compares이며 nearby places
Annual averages, and the difference against Illinois.
| Place | Distance | Avg temp | vs here | Annual rain |
|---|---|---|---|---|
| Gateway Arch National Park | 137 km | 15°C | +1°C warmer | 1156 mm |
| St. Louis | 137 km | 15°C | +1°C warmer | 1156 mm |
| Missouri | 255 km | 15°C | +1°C warmer | 1006 mm |
| Indianapolis | 298 km | 13°C | 1°C cooler | 1135 mm |
| Indiana | 298 km | 13°C | 1°C cooler | 1135 mm |
기후 by city in Illinois
1 cities mapped in this atlas
기후 by state park in Illinois
1 state and provincial parks mapped in this atlas
기후 by county in Illinois
1 counties mapped in this atlas
기후 by lake in Illinois
1 lakes mapped in this atlas
방문하기 좋은 시기 Illinois
Go in 8월, 9월 and 10월. These months score highest on comfortable temperatures, low rainfall and useful daylight.
Hardest months: 1월, 2월 and 12월 - expect the least comfortable mix of heat, cold or rain.
What this means for Illinois
Today is slightly warmer than average for 10월. The forecast high of 24°C is 3.7°C above the 20°C typical for this month.
비 is very unlikely today - plans do not need a backup.
No weather-related travel disruption is expected today. Roads and airports should run normally.
Northern Hemisphere, so peak summer falls in 6월에서 8월.
The gap between the warmest and coldest month averages 29°C.
What에서 pack, what에서 skip
- 일glasses, a brimmed hat and SPF 30+
- Layers - the daily swing is 20°C, so mornings feel nothing like afternoons
- If your dates are flexible, avoid 1월, 2월 and 12월 - historically the least comfortable months here.
요약
Illinois is a state in 미국. Illinois is a US state수도는 Springfield. 인구는 약 12.6 million. 수도는 Springfield.
현재 기온은 15°C (59°F) in Illinois이며 맑음. 체감온도는 13°C. 오늘 기온은 5°C에서 24°C. 강수 확률은 1%. Sightseeing conditions score 9.8/10 - 매우 좋음 — 지금 출발하세요.
방문하기 가장 좋은 시기는 Illinois is 8월, 9월 and 10월. 기후는 continental. 1월, 2월 and 12월 tend에서 be the least comfortable months. 7월 is the warmest month이며 average highs near 29°C, while 1월 is the coldest이며 lows near -7°C.
The closest major airport is O'Hare International Airport (ORD), about 284 km away. Nearby highlights include Starved Rock State Park, Lake Michigan, Gateway Arch National Park and Indiana Dunes National Park.
쉽게 말하면. Today is slightly warmer than average for 10월. The forecast high of 24°C is 3.7°C above the 20°C typical for this month. The best window에서 be outside is roughly 11 AM에서 2 PM, when temperature, rain chance and wind line up best. stargazing is the strongest bet in Illinois today at 10/10. No weather-related travel disruption is expected today. Roads and airports should run normally.
Compiled from this page's own data: atlas facts plus live Open-Meteo readings.
Quick facts about Illinois
날씨 map for Illinois
Animated model layers. Pick a layer에서 load it.
Animated layers by 바람y. For pin-level detail and nearby places, see the interactive map below.
Explore Illinois
Every topic we hold for this place, and the same topic for the places around it.
기후 for related places
Frequently asked questions
Where is Illinois?
Illinois is a state in 미국. Its coordinates are 39.7817, -89.6501. It lies in 북아메리카.
What is the weather like in Illinois 현재?
It is currently 15°C (59°F)이며 맑음. 습도 is 48% and wind is 6 km/h.
When is the best time에서 visit Illinois?
8월, 9월 and 10월 offer the most comfortable conditions in Illinois, which has a continental climate. 1월, 2월 and 12월 are usually the hardest months for outdoor plans.
What time zone is Illinois in?
Illinois observes America/Chicago (UTC-05:00). The local time is 12:18 AM.
How many people live in Illinois?
Illinois has a population of approximately 12.6 million.
What is the nearest airport에서 Illinois?
The closest airports are O'Hare International Airport (ORD), 284 km away and Nashville International Airport (BNA), 483 km away.
What are the top things에서 do in Illinois?
Popular options include Starved Rock State Park, Lake Michigan, Gateway Arch National Park and Indiana Dunes National Park.
What places are in Illinois?
Illinois covers 4 places in this atlas, including Chicago, Starved Rock State Park, Cook County and Lake Michigan.
Related articles
Data sources and methodology
| Place data | USPOTUS Atlas dataset (us-states) - coordinates, hierarchy and facts. |
|---|---|
| 예보 and observations | Open-Meteo (ECMWF and national models). |
| 대기질 and pollen | Copernicus CAMS via Open-Meteo. US AQI scale. |
| 기후 averages | ERA5 reanalysis via the Open-Meteo archive, aggregated over 3 years. |
| Official alerts | US National 날씨 Service. |
| Method | Scores, comparisons and advice on this page are computed from the inputs above. Distances are straight-line. Nothing is estimated where data is missing - the block is simply not shown. |
Last updated 10월 22, 2026 at 12:18 AM local time. Live blocks refresh every 15 minutes; climate averages monthly.
