St. Helena, CA Weather & Climate Normals
What a normal year in St. Helena actually looks like
On the 30-year record NOAA keeps for St. Helena, CA, the comfort score comes out to 72/100, mild with real seasons: A solid stretch of comfortable months alongside a noticeable but not extreme summer or winter. Only 8 months a year land in the 55–75°F range this site treats as mild.
How much St. Helena's weather actually swings
Average temperatures in St. Helena run from 49°F in Dec up to 72°F in Jul, a 23.4°F seasonal swing, a middling gap by national standards.
St. Helena, month by month
| Month | Avg high | Avg low | Precip | Snow |
|---|---|---|---|---|
| Jan | 59°F | 40°F | 6.47in | 0in |
| Feb | 63°F | 42°F | 6.71in | 0in |
| Mar | 67°F | 44°F | 4.98in | 0in |
| Apr | 72°F | 46°F | 1.97in | 0in |
| May | 78°F | 51°F | 1.31in | 0in |
| Jun | 85°F | 54°F | 0.35in | 0in |
| Jul | 89°F | 56°F | 0.01in | 0in |
| Aug | 89°F | 56°F | 0.04in | 0in |
| Sep | 87°F | 54°F | 0.06in | 0in |
| Oct | 78°F | 49°F | 1.65in | 0in |
| Nov | 66°F | 44°F | 3.24in | 0in |
| Dec | 58°F | 40°F | 7.18in | 0in |
If you're timing a visit, most of the year (8 of 12 months) are St. Helena's mildest stretch; if you're moving there, you should plan around Dec's cold instead.
How wet St. Helena actually gets
Over a typical year, St. Helena sees about 33.97in of precipitation a year across roughly 69 days with measurable rain or snow, with 0in of snow a year.
St. Helena against the rest of the country
Out of 4876 cities scored here, St. Helena comes in at 237; within CA alone it ranks 233 of 429. Population is about 5,257.
Checking the actual forecast
These figures come from Saint Helena, CA US, the NOAA station 0.5 miles from St. Helena, averaged over 30 years, not tomorrow's forecast.
More on how this is worked out
Why this uses the nearest NOAA station · How the comfort score is calculated