Illinois Καιρός Πρόγνωση
Illinois weather: 14°C, Κυρίως αίθριος. Ανά ώρα forecast, 14-day outlook, UV, air quality and the best time έως visit.
Illinois weather in Δεκέμβριος
One of the harder months here - go in με a plan.
Δεκέμβριος runs 11°C cooler than the annual average in Illinois.
Καιρός map for Illinois
Animated model layers. Pick a layer έως load it.
Animated layers by Άνεμοςy. For pin-level detail and nearby places, see the interactive map below.
Κλίμα in Illinois month by month
Average high, average low and total rainfall, based on three years of reanalysis data.
| Μήνας | Avg high | Avg low | Βροχήfall | Rating |
|---|---|---|---|---|
| Ιανουάριος | 1° | -7° | 62 mm | ★★☆☆☆ |
| Φεβρουάριος | 8° | -3° | 20 mm | ★★★☆☆ |
| Μάρτιος | 15° | 4° | 90 mm | ★★★☆☆ |
| Απρίλιος | 19° | 9° | 135 mm | ★★★☆☆ |
| Μάι | 24° | 13° | 100 mm | ★★★★☆ |
| Ιούνιος | 28° | 19° | 117 mm | ★★★★☆ |
| Ιούλιος | 29° | 21° | 129 mm | ★★★★☆ |
| Αύγουστος | 29° | 19° | 75 mm | ★★★★☆ |
| Σεπτέμβριος | 28° | 17° | 33 mm | ★★★★★ |
| Οκτώβριος | 20° | 10° | 37 mm | ★★★★☆ |
| Νοέμβριος | 12° | 4° | 79 mm | ★★★☆☆ |
| Δεκέμβριος | 6° | -2° | 62 mm | ★★☆☆☆ |
Κλίμα type: Ήπειροςal. Πηγή: Open-Meteo archive (ERA5).
Καλύτερη εποχή για επίσκεψη Illinois
Go in Αύγουστος, Σεπτέμβριος and Οκτώβριος. These months score highest on comfortable temperatures, low rainfall and useful daylight.
Hardest months: Ιανουάριος, Φεβρουάριος and Δεκέμβριος - expect the least comfortable mix of heat, cold or rain.
What έως pack, what έως skip
- Κυρglasses, 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 Ιανουάριος, Φεβρουάριος and Δεκέμβριος - historically the least comfortable months here.
How Illinois compares με 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 |
Δείτε την πρόγνωση για Illinois ανά χρονικό διάστημα
Illinois weather - more answers
Explore Illinois
Every topic we hold for this place, and the same topic for the places around it.
Καιρός for related places
Frequently asked questions
Where is Illinois?
Illinois is a state in Ηνωμένες Πολιτείες. Its coordinates are 39.7817, -89.6501. It lies in Βόρεια Αμερική.
What is the weather like in Illinois τώρα?
It is currently 14°C (57°F) με Κυρίως αίθριος. Υγρασία is 71% and wind is 7 km/h.
When is the best time έως visit Illinois?
Αύγουστος, Σεπτέμβριος and Οκτώβριος offer the most comfortable conditions in Illinois, which has a continental climate. Ιανουάριος, Φεβρουάριος and Δεκέμβριος 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 7:59 AM.
How many people live in Illinois?
Illinois has a population of approximately 12.6 million.
What is the nearest airport έως 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 έως 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. |
|---|---|
| Πρόγνωση and observations | Open-Meteo (ECMWF and national models). |
| Ποιότητα αέρα and pollen | Copernicus CAMS via Open-Meteo. US AQI scale. |
| Κλίμα averages | ERA5 reanalysis via the Open-Meteo archive, aggregated over 3 years. |
| Official alerts | US National Καιρός 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 Οκτώβριος 26, 2026 at 7:59 AM local time. Live blocks refresh every 15 minutes; climate averages monthly.
