Sunshine hours in Seattle: 2,170 hours a year, month by month

Seattle gets 2,170 hours of sunshine a year on average (5.9 a day). Sunniest month: July with 312 hours. Every month, measured 1961–1990.

• Seattle gets 2,170 hours of sunshine a year on average, 5.9 a day – 49% of the astronomically possible. The sunniest month is July with 312 hours (10.1 a day), the dullest December with 53 (1.7 a day).
• Number 304 of 311 large cities in the United States.
• Nearest weather station: Seattle/Seattle-Tacoma Intl A, WA, 20 km away – 1961–1990 average, NOAA.

Sunshine hours month by month

• January: 70 h · 2.3 h a day · 25 %
• February: 109 h · 3.9 h a day · 38 %
• March: 178 h · 5.7 h a day · 48 %
• April: 207 h · 6.9 h a day · 51 %
• May: 254 h · 8.2 h a day · 54 %
• June: 268 h · 8.9 h a day · 56 %
• July: 312 h · 10.1 h a day · 65 %
• August: 281 h · 9.1 h a day · 64 %
• September: 222 h · 7.4 h a day · 59 %
• October: 143 h · 4.6 h a day · 42 %
• November: 73 h · 2.4 h a day · 26 %
• December: 53 h · 1.7 h a day · 20 %

Questions about sunshine hours

• How many hours of sunshine does Seattle get a year? On average over 1961–1990 the sun shines in Seattle for 2,170 hours a year – 5.9 hours a day and 49% of the time the sun is above the horizon.
• What is the sunniest month in Seattle? July, with 312 hours of sunshine, 10.1 a day on average. The least sun comes in December: 53 hours, 1.7 a day.
• Is Seattle a sunny city? Among the 311 large cities in the United States with measurements, Seattle ranks number 304.
• 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. Seattle uses the station Seattle/Seattle-Tacoma Intl A, WA, 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.