Sunshine hours in Santa Rosa: 3,060 hours a year, month by month

Santa Rosa gets 3,060 hours of sunshine a year on average (8.4 a day). Sunniest month: May with 325 hours. Every month, measured 1961–1974.

• Santa Rosa gets 3,060 hours of sunshine a year on average, 8.4 a day – 69% of the astronomically possible. The sunniest month is May with 325 hours (10.5 a day), the dullest December with 161 (5.2 a day).
• Number 104 of 311 large cities in the United States.
• Nearest weather station: San Francisco/Mission Dolores, CA, 76 km away – 1961–1974 average, NOAA.

Sunshine hours month by month

• January: 186 h · 6.0 h a day · 61 %
• February: 208 h · 7.4 h a day · 69 %
• March: 269 h · 8.7 h a day · 73 %
• April: 309 h · 10.3 h a day · 78 %
• May: 325 h · 10.5 h a day · 74 %
• June: 311 h · 10.4 h a day · 70 %
• July: 313 h · 10.1 h a day · 69 %
• August: 287 h · 9.3 h a day · 68 %
• September: 271 h · 9.0 h a day · 73 %
• October: 247 h · 8.0 h a day · 71 %
• November: 173 h · 5.8 h a day · 57 %
• December: 161 h · 5.2 h a day · 54 %

Questions about sunshine hours

• How many hours of sunshine does Santa Rosa get a year? On average over 1961–1974 the sun shines in Santa Rosa for 3,060 hours a year – 8.4 hours a day and 69% of the time the sun is above the horizon.
• What is the sunniest month in Santa Rosa? May, with 325 hours of sunshine, 10.5 a day on average. The least sun comes in December: 161 hours, 5.2 a day.
• Is Santa Rosa a sunny city? Among the 311 large cities in the United States with measurements, Santa Rosa ranks number 104.
• 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. Santa Rosa uses the station San Francisco/Mission Dolores, CA, measured 1961–1974.
• 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, 1961–1974 average, public domain. Possible hours: time between sunrise and sunset.