Illinois 氣候 and Average 天氣
氣候 of Illinois: average temperatures, rainfall and seasons month by month.
氣候 in Illinois month by month
Average high, average low and total rainfall, based on three years of reanalysis data.
| 月份 | Avg high | Avg low | 雨fall | Rating |
|---|---|---|---|---|
| 一月 | 1° | -7° | 62 mm | ★★☆☆☆ |
| 二月 | 8° | -3° | 20 mm | ★★★☆☆ |
| 三月 | 15° | 4° | 90 mm | ★★★☆☆ |
| 四月 | 19° | 9° | 135 mm | ★★★☆☆ |
| 五月 | 24° | 13° | 100 mm | ★★★★☆ |
| 六月 | 28° | 19° | 117 mm | ★★★★☆ |
| 七月 | 29° | 21° | 129 mm | ★★★★☆ |
| 八月 | 29° | 19° | 75 mm | ★★★★☆ |
| 九月 | 28° | 17° | 33 mm | ★★★★★ |
| 十月 | 20° | 10° | 37 mm | ★★★★☆ |
| 十一月 | 12° | 4° | 79 mm | ★★★☆☆ |
| 十二月 | 6° | -2° | 62 mm | ★★☆☆☆ |
氣候 type: 洲al. 來源： Open-Meteo archive (ERA5).
Recent extremes in Illinois
高est and lowest readings observed in the last 3 years of reanalysis data - not all-time records.
How Illinois compares，天氣為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 |
氣候 by city in Illinois
1 cities mapped in this atlas
氣候 by state park in Illinois
1 state and provincial parks mapped in this atlas
氣候 by county in Illinois
1 counties mapped in this atlas
氣候 by lake in Illinois
1 lakes mapped in this atlas
最佳旅遊時間 Illinois
Go in 八月, 九月 and 十月. These months score highest on comfortable temperatures, low rainfall and useful daylight.
Hardest months: 一月, 二月 and 十二月 - expect the least comfortable mix of heat, cold or rain.
What this means for Illinois
Today is warmer than average for 十月. The forecast high of 25°C is 5.1°C above the 20°C typical for this month.
雨 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 六月至八月.
The gap between the warmest and coldest month averages 29°C.
What至pack, what至skip
- 週日glasses, a brimmed hat and SPF 30+
- Layers - the daily swing is 19°C, so mornings feel nothing like afternoons
- If your dates are flexible, avoid 一月, 二月 and 十二月 - historically the least comfortable months here.
摘要
Illinois is a state in 美國. Illinois is a US state，首都是Springfield. 人口約為12.6 million. 首都是Springfield.
目前氣溫為14°C (57°F) in Illinois，天氣為大致晴朗. 體感溫度為13°C. 今天氣溫介於7°C至25°C. 降雨機率為0%. Sightseeing conditions score 9.6/10 - 極佳 — 現在適合出發.
最佳旅遊時間是Illinois is 八月, 九月 and 十月. 氣候為continental. 一月, 二月 and 十二月 tend至be the least comfortable months. 七月 is the warmest month，天氣為average highs near 29°C, while 一月 is the coldest，天氣為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.
簡單來說。 Today is warmer than average for 十月. The forecast high of 25°C is 5.1°C above the 20°C typical for this month. The best window至be outside is roughly 11 AM至2 PM, when temperature, rain chance and wind line up best. hiking is the strongest bet in Illinois today at 9.8/10. 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
天氣 map for Illinois
Animated model layers. Pick a layer至load it.
Animated layers by 風y. 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.
氣候 for related places
Frequently asked questions
Where is Illinois?
Illinois is a state in 美國. Its coordinates are 39.7817, -89.6501. It lies in 北美洲.
What is the weather like in Illinois現在?
It is currently 14°C (57°F)，天氣為大致晴朗. 濕度 is 71% and wind is 7 km/h.
When is the best time至visit Illinois?
八月, 九月 and 十月 offer the most comfortable conditions in Illinois, which has a continental climate. 一月, 二月 and 十二月 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 12:08 AM.
How many people live in Illinois?
Illinois has a population of approximately 12.6 million.
What is the nearest airport至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 things至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. |
|---|---|
| 預報 and observations | Open-Meteo (ECMWF and national models). |
| 空氣品質 and pollen | Copernicus CAMS via Open-Meteo. US AQI scale. |
| 氣候 averages | ERA5 reanalysis via the Open-Meteo archive, aggregated over 3 years. |
| Official alerts | US National 天氣 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 十月 26, 2026 at 12:08 AM local time. Live blocks refresh every 15 minutes; climate averages monthly.
