Sunshine hours in Chicago: 2,507 hours a year, month by month

Chicago gets 2,507 hours of sunshine a year on average (6.9 a day). Sunniest month: July with 318 hours. Every month, measured 1961–1990.

• Chicago gets 2,507 hours of sunshine a year on average, 6.9 a day – 56% of the astronomically possible. The sunniest month is July with 318 hours (10.3 a day), the dullest December with 106 (3.4 a day).
• Number 266 of 311 large cities in the United States.
• Nearest weather station: Chicago/O'Hare, IL, 25 km away – 1961–1990 average, NOAA.

Sunshine hours month by month

• January: 136 h · 4.4 h a day · 46 %
• February: 136 h · 4.9 h a day · 46 %
• March: 187 h · 6.0 h a day · 51 %
• April: 215 h · 7.2 h a day · 54 %
• May: 282 h · 9.1 h a day · 63 %
• June: 311 h · 10.4 h a day · 68 %
• July: 318 h · 10.3 h a day · 69 %
• August: 283 h · 9.1 h a day · 66 %
• September: 227 h · 7.6 h a day · 61 %
• October: 193 h · 6.2 h a day · 56 %
• November: 113 h · 3.8 h a day · 38 %
• December: 106 h · 3.4 h a day · 37 %

Questions about sunshine hours

• How many hours of sunshine does Chicago get a year? On average over 1961–1990 the sun shines in Chicago for 2,507 hours a year – 6.9 hours a day and 56% of the time the sun is above the horizon.
• What is the sunniest month in Chicago? July, with 318 hours of sunshine, 10.3 a day on average. The least sun comes in December: 106 hours, 3.4 a day.
• Is Chicago a sunny city? Among the 311 large cities in the United States with measurements, Chicago ranks number 266.
• Where do the figures come from? From the WMO climate normals 1961–1990 as archived by NOAA. There are no newer figures: the US stopped measuring sunshine duration in the 1990s. Chicago uses the station Chicago/O'Hare, IL, measured 1961–1990.
• What counts as an hour of sunshine? By the World Meteorological Organization's definition the sun is shining once its direct radiation exceeds 120 watts per square metre. Just after sunrise and before sunset it is often too weak – which is why even deserts never reach 100%.

The sunniest large cities: United States

• 1. Phoenix: 3,873 h a year
• 2. Las Vegas: 3,826 h a year
• 3. Tucson: 3,806 h a year
• 4. Reno: 3,647 h a year
• 5. Sacramento: 3,609 h a year
• 6. Fresno: 3,565 h a year
• 7. Chico: 3,542 h a year
• 8. Colorado Springs: 3,463 h a year
• 9. Albuquerque: 3,414 h a year
• 10. Amarillo: 3,298 h a year

The cloudiest large cities: United States

• 1. Pittsburgh: 1,972 h a year
• 2. Anchorage: 2,063 h a year
• 3. Syracuse: 2,120 h a year
• 4. Seattle: 2,170 h a year
• 5. Columbus: 2,182 h a year
• 6. Grand Rapids: 2,188 h a year
• 7. Buffalo: 2,206 h a year
• 8. Meads: 2,259 h a year
• 9. Cleveland: 2,281 h a year
• 10. Rochester: 2,299 h a year

The sunniest large cities in the world

• 1. Mexicali: 4,017 h a year
• 2. Phoenix: 3,873 h a year
• 3. Las Vegas: 3,826 h a year
• 4. Tucson: 3,806 h a year
• 5. Ciudad Juárez: 3,763 h a year
• 6. Reno: 3,647 h a year
• 7. Dubai: 3,610 h a year
• 8. Sacramento: 3,609 h a year
• 9. Victoria de Durango: 3,573 h a year
• 10. Fresno: 3,565 h a year

The cloudiest large cities in the world

• 1. Chengdu: 962 h a year
• 2. Chongqing: 985 h a year
• 3. Sukabumi: 1,082 h a year
• 4. Glasgow: 1,153 h a year
• 5. Tanjung Pinang: 1,172 h a year
• 6. Medan: 1,201 h a year
• 7. Samarinda: 1,275 h a year
• 8. Sungai Penuh: 1,311 h a year
• 9. Limerick: 1,339 h a year
• 10. Huaihua: 1,352 h a year

• Data: NOAA, WMO climate normals of sunshine duration, 1961–1990 average, public domain. Possible hours: time between sunrise and sunset.