Illinois المناخ and Average الطقس
المناخ of Illinois: average temperatures, rainfall and seasons month by month.
المناخ in Illinois month by month
Average high, average low and total rainfall, based on three years of reanalysis data.
| الشهر | Avg high | Avg low | مطرfall | Rating |
|---|---|---|---|---|
| يناير | 1° | -7° | 62 mm | ★★☆☆☆ |
| فبراير | 8° | -3° | 20 mm | ★★★☆☆ |
| مارس | 15° | 4° | 90 mm | ★★★☆☆ |
| أبريل | 19° | 9° | 135 mm | ★★★☆☆ |
| ماي | 24° | 13° | 100 mm | ★★★★☆ |
| يونيو | 28° | 19° | 117 mm | ★★★★☆ |
| يوليو | 29° | 21° | 129 mm | ★★★★☆ |
| أغسطس | 28° | 19° | 47 mm | ★★★★☆ |
| سبتمبر | 27° | 16° | 42 mm | ★★★★☆ |
| أكتوبر | 20° | 10° | 37 mm | ★★★★☆ |
| نوفمبر | 12° | 4° | 79 mm | ★★★☆☆ |
| ديسمبر | 6° | -2° | 62 mm | ★★☆☆☆ |
المناخ type: القارةal. المصدر: Open-Meteo archive (ERA5).
Recent extremes in Illinois
مرتفعest and lowest readings observed in the last 3 years of reanalysis data - not all-time records.
How Illinois compares مع 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 | 1144 mm |
| St. Louis | 137 km | 15°C | +1°C warmer | 1144 mm |
| Missouri | 255 km | 14°C | +1°C warmer | 1002 mm |
| Indianapolis | 298 km | 13°C | 1°C cooler | 1094 mm |
| Indiana | 298 km | 13°C | 1°C cooler | 1094 mm |
المناخ by city in Illinois
1 cities mapped in this atlas
المناخ by state park in Illinois
1 state and provincial parks mapped in this atlas
المناخ by county in Illinois
1 counties mapped in this atlas
المناخ by lake in Illinois
1 lakes mapped in this atlas
أفضل وقت للزيارة Illinois
Go in أغسطس, سبتمبر and أكتوبر. These months score highest on comfortable temperatures, low rainfall and useful daylight.
Hardest months: يناير, فبراير and ديسمبر - expect the least comfortable mix of heat, cold or rain.
What this means for Illinois
Today is slightly warmer than average for أغسطس. The forecast high of 30°C is 2°C above the 28°C typical for this month.
A 11% chance means most of the area stays dry; a passing shower is possible but short.
No weather-related travel disruption is expected today. Roads and airports should run normally.
Northern Hemisphere, so peak summer falls in يونيو و أغسطس.
The gap between the warmest and coldest month averages 29°C.
What و pack, what و skip
- Lightweight, light-coloured clothing and a refillable water bottle
- الأحدglasses, a brimmed hat and SPF 30+
- If your dates are flexible, avoid يناير, فبراير and ديسمبر - historically the least comfortable months here.
الملخص
Illinois is a state in الولايات المتحدة. Illinois is a US state وعاصمتها Springfield. يبلغ عدد سكانها نحو 12.6 million. العاصمة هي Springfield.
درجة الحرارة الآن 22°C (71°F) in Illinois مع سماء صافية. المحسوسة 23°C. تتراوح درجات الحرارة اليوم بين 16°C و 30°C. احتمال هطول الأمطار 11%. Sightseeing conditions score 9.6/10 - ممتاز — انطلق الآن.
أفضل وقت لزيارة Illinois is أغسطس, سبتمبر and أكتوبر. المناخ continental. يناير, فبراير and ديسمبر tend و be the least comfortable months. يوليو is the warmest month مع average highs near 29°C, while يناير is the coldest مع 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.
باختصار. Today is slightly warmer than average for أغسطس. The forecast high of 30°C is 2°C above the 28°C typical for this month. The best window و be outside is roughly 7 AM و 10 AM, when temperature, rain chance and wind line up best. stargazing is the strongest bet in Illinois today at 9.7/10. 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
| النوع | State |
|---|---|
| الدولة | الولايات المتحدة |
| القارة | أمريكا الشمالية |
| الإحداثيات | 39°46′54.1″N 89°39′0.4″W (39.7817, -89.6501) |
| Capital | Springfield |
| السكان | 12.600.000 |
| Area | 149.995 km² |
| Abbreviation | IL |
| المنطقة الزمنية | America/Chicago |
| التوقيت المحلي | 10:38 AM (UTC-05:00) |
| Best months | أغسطس, سبتمبر and أكتوبر |
| المناخ | القارةal |
الطقس map for Illinois
Animated model layers. Pick a layer و load it.
Animated layers by الرياحy. 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.
المناخ for related places
Frequently asked questions
Where is Illinois?
Illinois is a state in الولايات المتحدة. Its coordinates are 39.7817, -89.6501. It lies in أمريكا الشمالية.
What is the weather like in Illinois الآن?
It is currently 22°C (71°F) مع سماء صافية. الرطوبة is 70% and wind is 5 km/h.
When is the best time و visit Illinois?
أغسطس, سبتمبر and أكتوبر offer the most comfortable conditions in Illinois, which has a continental climate. يناير, فبراير and ديسمبر 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 10:38 AM.
How many people live in Illinois?
Illinois has a population of approximately 12.6 million.
What is the nearest airport و 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 و 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. |
|---|---|
| التوقعات and observations | Open-Meteo (ECMWF and national models). |
| جودة الهواء and pollen | Copernicus CAMS via Open-Meteo. US AQI scale. |
| المناخ averages | ERA5 reanalysis via the Open-Meteo archive, aggregated over 3 years. |
| Official alerts | US National الطقس 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 أغسطس 21, 2026 at 10:38 AM local time. Live blocks refresh every 15 minutes; climate averages monthly.
