Illinois Vejr Prognose
Illinois weather: 15°C, delvist skyet. Hver time forecast, 14-day outlook, UV, air quality and the best time og visit.
Sne forecast for Illinois
No snow is in the current forecast window for Illinois.
0 of the next 16 nights are forecast og reach freezing.
Historically, average lows drop below freezing in januar, februar and december.
16-day forecast for Illinois
Maks. / Min.; Nedbør; UV
| Dag | Forhold | Maks. / Min. | Nedbør | Vind | UV |
|---|---|---|---|---|---|
| fre, okt 2 | 🌦️ Støvregn | 20° / 12° | 43% · 1 mm | 20 km/h | 6 |
| lør, okt 3 | ☀️ Klar himmel | 22° / 8° | 1% | 13 km/h | 5 |
| søn, okt 4 | ☁️ Overskyet | 26° / 13° | 0% | 18 km/h | 5 |
| man, okt 5 | ☀️ Klar himmel | 23° / 10° | 0% | 17 km/h | 5 |
| tir, okt 6 | ⛅ Delvist skyet | 23° / 8° | 0% | 14 km/h | 5 |
| ons, okt 7 | ☁️ Overskyet | 29° / 11° | 1% | 19 km/h | 5 |
| tor, okt 8 | ☁️ Overskyet | 32° / 16° | 0% | 26 km/h | 5 |
| fre, okt 9 | ☀️ Klar himmel | 24° / 13° | 1% | 19 km/h | 5 |
| lør, okt 10 | ☀️ Klar himmel | 28° / 10° | 1% | 22 km/h | 5 |
| søn, okt 11 | ☀️ Klar himmel | 32° / 17° | 9% | 33 km/h | 5 |
| man, okt 12 | 🌧️ Byger | 30° / 17° | 11% · 12 mm | 29 km/h | 5 |
| tir, okt 13 | 🌦️ Light drizzle | 17° / 12° | 6% · 0 mm | 39 km/h | 2 |
| ons, okt 14 | ☀️ Klar himmel | 21° / 8° | 11% | 20 km/h | 5 |
| tor, okt 15 | ☀️ Klar himmel | 24° / 11° | 13% | 31 km/h | 5 |
| fre, okt 16 | ⛅ Delvist skyet | 28° / 7° | 11% | 38 km/h | 5 |
| lør, okt 17 | ☀️ Klar himmel | 12° / 4° | 10% | 29 km/h | 4 |
Klima in Illinois month by month
Average high, average low and total rainfall, based on three years of reanalysis data.
| Måned | Avg high | Avg low | Regnfall | Rating |
|---|---|---|---|---|
| januar | 1° | -7° | 62 mm | ★★☆☆☆ |
| februar | 8° | -3° | 20 mm | ★★★☆☆ |
| marts | 15° | 4° | 90 mm | ★★★☆☆ |
| april | 19° | 9° | 135 mm | ★★★☆☆ |
| maj | 24° | 13° | 100 mm | ★★★★☆ |
| juni | 28° | 19° | 117 mm | ★★★★☆ |
| juli | 29° | 21° | 129 mm | ★★★★☆ |
| august | 29° | 19° | 75 mm | ★★★★☆ |
| september | 28° | 17° | 33 mm | ★★★★★ |
| oktober | 20° | 10° | 37 mm | ★★★★☆ |
| november | 12° | 4° | 79 mm | ★★★☆☆ |
| december | 6° | -2° | 62 mm | ★★☆☆☆ |
Klima type: Kontinental. Kilde: Open-Meteo archive (ERA5).
What og pack, what og skip
- Lightweight, light-coloured clothing and a refillable water bottle
- sønglasses, a brimmed hat and SPF 30+
- Layers - the daily swing is 24°C, so mornings feel nothing like afternoons
- If your dates are flexible, avoid januar, februar and december - historically the least comfortable months here.
Se prognosen for Illinois efter tidsinterval
Illinois weather - more answers
Explore Illinois
Every topic we hold for this place, and the same topic for the places around it.
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Frequently asked questions
Where is Illinois?
Illinois is a state in USA. Its coordinates are 39.7817, -89.6501. It lies in Nordamerika.
What is the weather like in Illinois lige nu?
It is currently 15°C (59°F) med delvist skyet. Luftfugtighed is 77% and wind is 16 km/h.
When is the best time og visit Illinois?
august, september and oktober offer the most comfortable conditions in Illinois, which has a continental climate. januar, februar and december 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 8:43 AM.
How many people live in Illinois?
Illinois has a population of approximately 12.6 million.
What is the nearest airport og 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 og 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. |
|---|---|
| Prognose and observations | Open-Meteo (ECMWF and national models). |
| Luftkvalitet and pollen | Copernicus CAMS via Open-Meteo. US AQI scale. |
| Klima averages | ERA5 reanalysis via the Open-Meteo archive, aggregated over 3 years. |
| Official alerts | US National Vejr 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 oktober 2, 2026 at 8:43 AM local time. Live blocks refresh every 15 minutes; climate averages monthly.
