When does it actually rain in San Diego?
Between December and March, and barely then. February is the wettest month at about 2.2 inches. August averages essentially nothing. The whole year adds up to under 10 inches.
- Annual rainfall
- About 9.8 inches
- Wettest month
- February, about 2.2 in
- Driest stretch
- June – September
- Wet season
- December – March
250 mm, across ~40 rainy days
Close to zero
The short version
- San Diego averages about 250 mm — under 10 inches — of rain a year, across roughly 40 rainy days.
- December through March accounts for most of it; February is the wettest month at about 2.2 inches.
- June through September is effectively dry: four months that together average well under half an inch.
- Grey is not the same as wet — May and June are the cloudiest months on the coast and among the driest.
- When it does rain, stay out of the ocean for 72 hours afterwards.
San Diego's rainfall is not spread thinly across the year — it arrives in a short winter season and then stops almost entirely. Understanding the shape of it is more useful than the annual total, because the total makes the city sound merely dry while the distribution makes it sound like two different climates.
Average rainfall by month
San Diego — the whole year fits in four months
Source: Climates to Travel, converted from millimetres. Open the data view for the monthly figures.
Four months — December, January, February and March — carry roughly three quarters of the year's rain. The summer is not "dry-ish": August averages essentially zero, and June, July and September average a tenth of an inch or less each.
Rainy days per month
| Month | Rainy days |
|---|---|
| January | 6 |
| February | 7 |
| March | 6 |
| April | 4 |
| May | 2 |
| June | 1 |
| July | 1 |
| August | 0 |
| September | 1 |
| October | 2 |
| November | 4 |
| December | 6 |
About 40 days a year with measurable rain. Source: Climates to Travel.
One caveat on any average: San Diego's rainfall is highly variable year to year. A single atmospheric river can deliver a large share of a season's total in two days, and El Niño and La Niña winters look nothing like each other. The monthly shape above is reliable; any given year is not.
KEEP READING
SOURCES
Everything above traces back to one of these. Follow them — if one has changed and we haven't, that's our mistake, not yours.
Climates to Travel · Checked September 8, 2026
Monthly rainfall in millimetres, rainy-day counts, and the 250 mm annual total.
NOAA · Ongoing
Current forecasts and the seasonal outlooks behind the wet-season framing.
San Diego County Department of Environmental Health and Quality · Checked September 8, 2026
The 72-hour post-rain water contact advisory referenced above.