Cook County Population (2026)
Population of Cook County with area, density and how it compares to nearby places.
Population of Cook County
Quick facts about Cook County
| Type | County |
|---|---|
| State | Illinois |
| Country | United States |
| Continent | North America |
| Coordinates | 41°52′41.2″N 87°37′47.3″W (41.8781, -87.6298) |
| Population | 5.100.000 |
| Local time | 11:22 PM (UTC-05:00) |
| Best months | May, June, August, September and October |
| Climate | Continental |
Summary
Cook County is a county in Illinois. Cook County is a county in the United States. It has a population of about 5.1 million.
Right now it is 61°F (16°C) in Cook County with overcast. It feels like 63°F. Today runs from 59°F to 65°F. Chance of precipitation is 92%. Sightseeing conditions score 7.5/10 - good conditions.
The best time to visit Cook County is May, June, August, September and October. The climate is continental. January, February and December tend to be the least comfortable months. July is the warmest month with average highs near 82°F, while January is the coldest with lows near 17°F.
The closest major airport is O'Hare International Airport (ORD), about 16 mi away. Nearby highlights include Indiana Dunes National Park, Starved Rock State Park and Lake Michigan.
In plain terms. Today is cooler than average for September. The forecast high of 65°F is 10.6°F below the 76°F typical for this month. The best window to be outside is roughly 10 AM to 1 PM, when temperature, rain chance and wind line up best. fishing is the strongest bet in Cook County today at 9.7/10. Wet roads are likely; braking distances roughly double in heavy rain.
Compiled from this page's own data: atlas facts plus live Open-Meteo readings.
Map of Cook County
Interactive map with nearby places. Switch between street, terrain and satellite views.
Coordinates: 41°52′41.2″N 87°37′47.3″W (41.8781, -87.6298)
Explore Cook County
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Frequently asked questions
Where is Cook County?
Cook County is a county in Illinois. Its coordinates are 41.8781, -87.6298. It lies in North America.
What is the weather like in Cook County right now?
It is currently 61°F (16°C) with overcast. Humidity is 93% and wind is 3 mph.
When is the best time to visit Cook County?
May, June, August, September and October offer the most comfortable conditions in Cook County, which has a continental climate. January, February and December are usually the hardest months for outdoor plans.
What time zone is Cook County in?
Cook County observes America/Chicago (UTC-05:00). The local time is 11:22 PM.
How many people live in Cook County?
Cook County has a population of approximately 5.1 million.
What is the nearest airport to Cook County?
The closest airports are O'Hare International Airport (ORD), 16 mi away.
What are the top things to do in Cook County?
Popular options include Indiana Dunes National Park, Starved Rock State Park and Lake Michigan.
Related articles
Data sources and methodology
| Place data | USPOTUS Atlas dataset (us-counties) - coordinates, hierarchy and facts. |
|---|---|
| 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 September 30, 2026 at 11:22 PM local time. Live blocks refresh every 15 minutes; climate averages monthly.
