WeatherWX.comSt Helens Monthly Climate Averages
January |
February |
March |
April |
May |
June |
July |
August |
September |
October |
November |
December |
| Hi 44°F Lo 36°F | Hi 46°F Lo 36°F | Hi 50°F Lo 38°F | Hi 56°F Lo 41°F | Hi 60°F Lo 45°F | Hi 66°F Lo 50°F | Hi 68°F Lo 54°F | Hi 67°F Lo 54°F | Hi 64°F Lo 51°F | Hi 57°F Lo 47°F | Hi 50°F Lo 42°F | Hi 45°F Lo 38°F |
| 10 mph | 11 mph | 10 mph | 9 mph | 8 mph | 7 mph | 8 mph | 8 mph | 8 mph | 9 mph | 10 mph | 10 mph |
| 1.9 in | 1.6 in | 1.4 in | 1.1 in | 1.6 in | 2 in | 2.2 in | 2.2 in | 1.6 in | 1.9 in | 2.1 in | 2 in |
| 87% | 84% | 80% | 77% | 78% | 79% | 79% | 79% | 81% | 84% | 86% | 87% |
| 61% | 61% | 54% | 49% | 52% | 53% | 54% | 54% | 52% | 58% | 61% | 61% |
| 29.9 in | 29.9 in | 30.0 in | 30.0 in | 30.0 in | 30.0 in | 29.9 in | 29.9 in | 30.0 in | 29.9 in | 29.8 in | 29.9 in |
| 21 | 19 | 26 | 26 | 27 | 25 | 27 | 27 | 27 | 26 | 24 | 23 |
| 7 | 6 | 4 | 3 | 4 | 5 | 4 | 4 | 3 | 5 | 5 | 6 |
| 3 | 3 | 1 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 2 |
| 3 | 2 | 2 | 3 | 4 | 5 | 6 | 5 | 4 | 2 | 2 | 2 |
| 2 | 2 | 2 | 3 | 4 | 4 | 4 | 4 | 3 | 3 | 2 | 2 |
| 214 | 191 | 235 | 247 | 242 | 234 | 246 | 252 | 247 | 228 | 212 | 213 |
January |
February |
March |
April |
May |
June |
July |
August |
September |
October |
November |
December |
| Hi 6°C Lo 2°C | Hi 8°C Lo 2°C | Hi 10°C Lo 3°C | Hi 13°C Lo 5°C | Hi 16°C Lo 7°C | Hi 19°C Lo 10°C | Hi 20°C Lo 12°C | Hi 20°C Lo 12°C | Hi 18°C Lo 11°C | Hi 14°C Lo 8°C | Hi 10°C Lo 5°C | Hi 7°C Lo 3°C |
| 16 km/h | 18 km/h | 15 km/h | 14 km/h | 14 km/h | 12 km/h | 12 km/h | 13 km/h | 13 km/h | 15 km/h | 16 km/h | 16 km/h |
| 47 mm | 40 mm | 36 mm | 27 mm | 40 mm | 51 mm | 56 mm | 56 mm | 40 mm | 47 mm | 54 mm | 50 mm |
| 87% | 84% | 80% | 77% | 78% | 79% | 79% | 79% | 81% | 84% | 86% | 87% |
| 61% | 61% | 54% | 49% | 52% | 53% | 54% | 54% | 52% | 58% | 61% | 61% |
| 1013 mb | 1012 mb | 1015 mb | 1016 mb | 1016 mb | 1016 mb | 1014 mb | 1014 mb | 1016 mb | 1013 mb | 1010 mb | 1011 mb |
| 21 | 19 | 26 | 26 | 27 | 25 | 27 | 27 | 27 | 26 | 24 | 23 |
| 7 | 6 | 4 | 3 | 4 | 5 | 4 | 4 | 3 | 5 | 5 | 6 |
| 3 | 3 | 1 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 2 |
| 3 | 2 | 2 | 3 | 4 | 5 | 6 | 5 | 4 | 2 | 2 | 2 |
| 2 | 2 | 2 | 3 | 4 | 4 | 4 | 4 | 3 | 3 | 2 | 2 |
| 214 | 191 | 235 | 247 | 242 | 234 | 246 | 252 | 247 | 228 | 212 | 213 |
| 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.
