El Niño in San Francisco
During El Niño, San Francisco gets on average 19% less rain in April–June than in neutral years (56 mm vs 69 mm).
Weather in San Francisco: next 7 days
San Francisco
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Weather forecast: MET Norway (CC BY 4.0), updated every hour. For official warnings, follow your national weather service.
El Niño is active right now: the El Niño columns show what San Francisco typically sees in this phase.
Monthly rainfall by phase
El NiñoNeutralLa Niña
Month by month
| Month | El Niño | Neutral | La Niña | Change El Niño | Temp. El Niño / neutral |
|---|---|---|---|---|---|
| January | 133 mm | 115 mm | 99 mm | +16% | 9.9 / 9.2 °C |
| February | 125 mm | 118 mm | 95 mm | +6% | 11.0 / 10.1 °C |
| March | 97 mm | 88 mm | 93 mm | +10% | 11.7 / 11.3 °C |
| April | 34 mm | 41 mm | 20 mm | -18% | 12.9 / 12.2 °C |
| May | 16 mm | 22 mm | 12 mm | -30% | 14.6 / 14.0 °C |
| June | 7 mm | 6 mm | 6 mm | +14% | 15.9 / 16.0 °C |
| July | 1 mm | 1 mm | 1 mm | — | 17.0 / 17.0 °C |
| August | 3 mm | 2 mm | 1 mm | — | 17.8 / 17.5 °C |
| September | 7 mm | 8 mm | 5 mm | -14% | 17.4 / 17.6 °C |
| October | 30 mm | 24 mm | 45 mm | +21% | 16.0 / 15.6 °C |
| November | 72 mm | 81 mm | 72 mm | -10% | 12.3 / 12.1 °C |
| December | 129 mm | 129 mm | 110 mm | 0% | 9.8 / 9.4 °C |
NASA POWER (MERRA-2), 1981–2025, classified by NOAA ONI. Averages, not a forecast.
Frequently asked questions
How does El Niño affect San Francisco?
During El Niño, San Francisco gets on average 19% less rain in April–June than in neutral years (56 mm vs 69 mm).
And La Niña?
In April–June, La Niña years average 38 mm, compared with 69 mm in neutral years.
Where does this data come from?
Monthly rainfall and temperature from NASA POWER (MERRA-2 reanalysis, 1981–2025) at 37.77, -122.42, classified by NOAA's Oceanic Niño Index for each month. These are averages; each event is different.