Chicago, United States
Chicago on one page: facts, climate by month, daylight and public holidays, each with its source.
- Population: 2,746,388 (City of Chicago, 2020 census)
- Warmest month: July, daily high 29.2 °C (84.6 °F), 1991-2020
- Coldest month: January, daily low -7.3 °C (18.9 °F), 1991-2020
- Wettest month: May, rain 114.0 mm (4.49 in), 1991-2020
- Most daylight: June, 15 h 13 min (15th of each month, 2026)
Warmest, coldest, wettest, most daylight: the highest or lowest of the 12 monthly values. Figures in brackets are converted: °F = °C × 9 ÷ 5 + 32, to 1 decimal; inches = mm ÷ 25.4, to 2 decimals.
Last updated : city answers rechecked against their sources.
What makes Chicago special
- Why does the river flow away from the lake?
- The city's early sewers ran straight into the river. So crews dug a huge canal that made the river flow the other way. Now waste water is sent away from Lake Michigan. That keeps the lake safe, and the region gets its drinking water from it. Source: Metropolitan Water Reclamation District, checked .
- Why did the city once lift whole buildings into the air?
- An engineer thought the streets sat too low for new sewers to drain. So the whole downtown was raised up. Workers lifted buildings with screw jacks and built new bases under them. Business owners had to pay, and some of them complained or went to court. Source: American Society of Civil Engineers, checked .
- Why is so much of the downtown lakefront kept as open park?
- Long ago, people feared that firms would build all along the shore, so they fought to save it. The land was set aside as public ground, to stay free of buildings for good. Later, a rich man who sold goods by mail sued to keep it open, and he won. Source: Chicago Park District, checked .
- What do the stars and stripes on the city flag stand for?
- Its three white bands mark the city's North, West and South Sides. The blue stripes stand for the lake, the river and a canal. Each red star marks an event from the city's past, such as the Great Chicago Fire. At the start, the flag had two stars. Source: Chicago Architecture Center, checked .
- Why do the bridges downtown tip up into the sky?
- Many are bascule bridges. They are named after the French word for a seesaw. They open by lifting up, not by turning to the side. Big boats once filled the narrow river, so the bridges had to open. On some mornings, they go up to let sailboats pass. Source: WBEZ, checked .
- Why does the river turn green for St. Patrick's Day?
- The local plumbers union backs it. As the plumbers tell it, their boss got the idea from a plumber's work clothes. They were stained green by dye used to track waste water. Now boats spread an orange powder that turns green in the water. The mix is kept secret. Source: WTTW, checked .
Facts
| Fact | Value and source |
|---|---|
| Country | United States Source: GeoNames dump, checked |
| Population | 2,746,388 (City of Chicago, 2020 census) Source: U.S. Census Bureau, checked |
| Area | 589.8 km² (City of Chicago, land, 2020) Converted from 227.73 square miles. Source: U.S. Census Bureau, checked |
| Coordinates | 41.8819° N, 87.6278° W rounded to four decimal places Source: Wikidata Query Service, checked |
| Time zone | America/ |
| Languages | English (official) Named official by Executive Order 14224 (1 March 2025), a presidential order, not an Act of Congress. Source: Executive Order 14224 (Federal Register), checked |
| Currency | US Dollar (USD) list dated 17 September 2026 Source: ISO 4217 list one (SIX Group), checked |
Climate by month
| Month | High, °C | Low, °C | Rain, mm | Sunshine, hours |
|---|---|---|---|---|
| Jan | -0.2 | -7.3 | 50.5 | no data |
| Feb | 2.1 | -5.7 | 50.0 | no data |
| Mar | 8.3 | -0.6 | 62.2 | no data |
| Apr | 15.0 | 4.6 | 95.3 | no data |
| May | 21.4 | 10.3 | 114.0 | no data |
| Jun | 26.9 | 16.0 | 104.1 | no data |
| Jul | 29.2 | 19.1 | 94.2 | no data |
| Aug | 28.1 | 18.4 | 108.0 | no data |
| Sep | 24.2 | 13.9 | 81.0 | no data |
| Oct | 17.1 | 7.4 | 87.1 | no data |
| Nov | 9.1 | 1.2 | 61.5 | no data |
| Dec | 2.6 | -4.2 | 53.6 | no data |
U.S. Climate Normals 1991-2020, NOAA. Checked .
High: mean daily maximum temperature. Low: mean daily minimum temperature. Rain: mean monthly precipitation total.
Notes. High and low: changed: source gives °F; converted to °C, rounded to 0.1. Rain: changed: source gives inches; converted to mm (x 25.4), rounded to 0.1. Sunshine: the NOAA U.S. monthly normals have no sunshine measure.
Daylight by month
| Month | Sunrise | Sunset | Day length |
|---|---|---|---|
| Jan | 07:16 | 16:45 | 9 h 29 min |
| Feb | 06:46 | 17:24 | 10 h 38 min |
| Mar | 07:02 | 18:57 | 11 h 55 min |
| Apr | 06:10 | 19:32 | 13 h 22 min |
| May | 05:30 | 20:04 | 14 h 34 min |
| Jun | 05:15 | 20:28 | 15 h 13 min |
| Jul | 05:29 | 20:24 | 14 h 55 min |
| Aug | 05:59 | 19:50 | 13 h 52 min |
| Sep | 06:31 | 19:00 | 12 h 29 min |
| Oct | 07:03 | 18:09 | 11 h 06 min |
| Nov | 06:40 | 16:30 | 9 h 49 min |
| Dec | 07:11 | 16:20 | 9 h 09 min |
Sunrise and sunset computed to the minute. Day length in hours and minutes. How we compute daylight
Source: NOAA Solar Calculator equations, checked .
Airports
| IATA code | Airport | Type | Distance, km |
|---|---|---|---|
| MDW | Chicago Midway International Airport | large airport | 15 |
| ORD | Chicago O'Hare International Airport | large airport | 25 |
Source: OurAirports airports.csv, checked .
Public holidays
| Date | Holiday |
|---|---|
| Thursday | New Year’s Day opm.gov |
| Monday | Birthday of Martin Luther King, Jr. opm.gov |
| Thursday | Lincoln's Birthday (Illinois state holiday) |
| Monday | Washington’s Birthday opm.gov |
| Monday | Memorial Day opm.gov |
| Friday | Juneteenth National Independence Day opm.gov |
| Friday | Independence Day (Federal holiday, observed on the Friday before) opm.gov |
| Monday | Labor Day opm.gov |
| Monday | Columbus Day opm.gov |
| Tuesday | General Election Day (Illinois state holiday) |
| Wednesday | Veterans Day opm.gov |
| Thursday | Thanksgiving Day opm.gov |
| Friday | Thanksgiving (Illinois state holiday: the day after Thanksgiving Day) |
| Friday | Christmas Day opm.gov |
| Date | Holiday |
|---|---|
| Friday | New Year’s Day opm.gov |
| Monday | Birthday of Martin Luther King, Jr. opm.gov |
| Friday | Lincoln's Birthday (Illinois state holiday) |
| Monday | Washington’s Birthday opm.gov |
| Monday | Memorial Day opm.gov |
| Friday | Juneteenth National Independence Day (Federal holiday, observed on the Friday before) opm.gov |
| Monday | Independence Day (Federal holiday, observed on the Monday after) opm.gov |
| Monday | Labor Day opm.gov |
| Monday | Columbus Day opm.gov |
| Thursday | Veterans Day opm.gov |
| Thursday | Thanksgiving Day opm.gov |
| Friday | Thanksgiving (Illinois state holiday: the day after Thanksgiving Day) |
| Friday | Christmas Day (Federal holiday, observed on the Friday before) opm.gov |
Typed from the official list and re-checked, .
Source: Official public holiday list (cms.illinois.gov), checked .
Landmarks
| Place | Kind | Lasting fact and source |
|---|---|---|
| The 20th-Century Architecture of Frank Lloyd Wright: Frederick C. Robie House | World Heritage site | UNESCO entry |
| Art Institute of Chicago | museum | Founded 1879, own site |
| Field Museum | museum | Opened to the public 1894, own site |
| Griffin Museum of Science and Industry | museum | Opened 1933, own site |
| Buckingham Fountain | historic site or monument | Opened to the public 1927, own site |
| Adler Planetarium | museum | Opened 1930, own site |
| Holy Name Cathedral | place of worship | Opened 1875, own site |
| ISAC Museum | museum | Opened to the public 1931, own site |
Sources: as named in each row, checked . How we choose landmarks
Other cities
In United States
Closest climate
Among the 20 cities with month pages, these have the monthly highs and lows nearest to Chicago's, averaged over the year. How we compare climates
Sources
- Wikidata Query Service, Wikimedia Foundation. Attribution: Wikidata. Licence: CC0 1.0. Checked .
- GeoNames dump (cities15000, countryInfo), GeoNames. Attribution: GeoNames, https://www.geonames.org/. Licence: CC BY 4.0. Checked .
- OurAirports airports.csv, OurAirports (David Megginson). Attribution: OurAirports. Licence: Public domain. Checked .
- U.S. Climate Normals 2020: U.S. Monthly Climate Normals (1991-2020), NOAA National Centers for Environmental Information. Attribution: Palecki, Michael; Durre, Imke; Applequist, Scott; Arguez, Anthony; Lawrimore, Jay (2021). U.S. Climate Normals 2020: U.S. Monthly Climate Normals (1991-2020). Station files named in each record. NOAA National Centers for Environmental Information. Dataset. https://doi.org/10.25921/wck8-er13. Accessed on the check date shown. Licence: No licence stated; citation requested. Checked .
- NOAA Solar Calculator equations, computed locally, NOAA Global Monitoring Laboratory (method); City by Month (computation). Attribution: Computed with the NOAA Solar Calculator method (no NOAA endorsement implied). Licence: Method, not data. Checked .
- IANA Time Zone Database, read through the PyPI tzdata package, IANA. Attribution: IANA Time Zone Database. Licence: Public-domain data. Checked .
Official sources
- Executive Order 14224 (Federal Register). Checked .
- ISO 4217 list one (SIX Group). Checked .
- Official public holiday list (cms.illinois.gov). Checked .
- U.S. Census Bureau. Also: www2.census.gov/geo/docs/maps-data/data/gazetteer/2020_Gazetteer/2020_gaz_place_17.txt. Checked .
Cite this page: City by Month. "Chicago, United States: facts and climate by month". https://citybymonth.com/cities/united-states/chicago/. Last updated 5 November 2026.