Weather World
Jefferson County, WA Official Website
Jefferson County Monthly Climate Averages
January |
February |
March |
April |
May |
June |
July |
August |
September |
October |
November |
December |
| Hi 38°F Lo 30°F | Hi 35°F Lo 27°F | Hi 38°F Lo 29°F | Hi 43°F Lo 32°F | Hi 51°F Lo 38°F | Hi 57°F Lo 43°F | Hi 65°F Lo 49°F | Hi 66°F Lo 51°F | Hi 60°F Lo 47°F | Hi 49°F Lo 40°F | Hi 41°F Lo 32°F | Hi 36°F Lo 28°F |
| 4 mph | 4 mph | 4 mph | 4 mph | 4 mph | 4 mph | 3 mph | 3 mph | 3 mph | 4 mph | 4 mph | 4 mph |
| 15.5 in | 11.1 in | 13.5 in | 7.9 in | 5 in | 3.6 in | 1.3 in | 2.3 in | 5.6 in | 11.5 in | 19.1 in | 20.2 in |
| 87% | 90% | 88% | 84% | 78% | 77% | 72% | 73% | 77% | 82% | 87% | 90% |
| 62% | 66% | 66% | 59% | 50% | 46% | 28% | 30% | 39% | 49% | 62% | 65% |
| 30.1 in | 30.0 in | 30.0 in | 30.0 in | 30.0 in | 30.0 in | 30.1 in | 30.0 in | 30.0 in | 29.9 in | 30.0 in | 30.0 in |
| 9 | 5 | 4 | 10 | 16 | 20 | 27 | 27 | 21 | 18 | 7 | 5 |
| 15 | 14 | 16 | 13 | 12 | 9 | 4 | 4 | 9 | 12 | 16 | 16 |
| 10 | 12 | 14 | 8 | 3 | 0 | 0 | 0 | 0 | 1 | 9 | 13 |
| 1 | 1 | 2 | 1 | 1 | 1 | 0 | 1 | 1 | 1 | 2 | 2 |
| 1 | 1 | 1 | 2 | 3 | 4 | 4 | 3 | 3 | 2 | 1 | 1 |
| 99 | 68 | 77 | 98 | 134 | 147 | 238 | 254 | 192 | 151 | 92 | 87 |
January |
February |
March |
April |
May |
June |
July |
August |
September |
October |
November |
December |
| Hi 3°C Lo -1°C | Hi 2°C Lo -3°C | Hi 3°C Lo -2°C | Hi 6°C Lo -0°C | Hi 11°C Lo 3°C | Hi 14°C Lo 6°C | Hi 18°C Lo 10°C | Hi 19°C Lo 10°C | Hi 15°C Lo 8°C | Hi 10°C Lo 4°C | Hi 5°C Lo 0°C | Hi 2°C Lo -2°C |
| 7 km/h | 7 km/h | 7 km/h | 6 km/h | 6 km/h | 6 km/h | 5 km/h | 5 km/h | 5 km/h | 6 km/h | 7 km/h | 7 km/h |
| 392 mm | 281 mm | 344 mm | 200 mm | 127 mm | 92 mm | 34 mm | 58 mm | 143 mm | 291 mm | 486 mm | 514 mm |
| 87% | 90% | 88% | 84% | 78% | 77% | 72% | 73% | 77% | 82% | 87% | 90% |
| 62% | 66% | 66% | 59% | 50% | 46% | 28% | 30% | 39% | 49% | 62% | 65% |
| 1018 mb | 1017 mb | 1016 mb | 1018 mb | 1017 mb | 1017 mb | 1018 mb | 1017 mb | 1015 mb | 1012 mb | 1016 mb | 1017 mb |
| 9 | 5 | 4 | 10 | 16 | 20 | 27 | 27 | 21 | 18 | 7 | 5 |
| 15 | 14 | 16 | 13 | 12 | 9 | 4 | 4 | 9 | 12 | 16 | 16 |
| 10 | 12 | 14 | 8 | 3 | 0 | 0 | 0 | 0 | 1 | 9 | 13 |
| 1 | 1 | 2 | 1 | 1 | 1 | 0 | 1 | 1 | 1 | 2 | 2 |
| 1 | 1 | 1 | 2 | 3 | 4 | 4 | 3 | 3 | 2 | 1 | 1 |
| 99 | 68 | 77 | 98 | 134 | 147 | 238 | 254 | 192 | 151 | 92 | 87 |
| Month |
| Avg. Temperatures |
| Avg. Wind Speed |
| Avg. Precipitation |
| Average Humidity |
| Avg. Cloud Cover |
| Pressure Average |
| Average Dry Days |
| Avg. Precip. Days |
| Avg. Snow Days |
| Average Fog Days |
| Average UV Index |
| Avg. Hours of Sun |
Averages are based on historical weather data from the past 10 years.