Hillsborough, CA
Climate overview — based on NOAA 1991-2020 normals from SAN FRANCISCO INTL AP, CA US.
Year-round temperatures (°F)
Climate summary
Hillsborough has an annual average temperature of 58.7°F with about 19.6 inches of precipitation per year. The warmest month is September (average high 74.8°F), and the coldest is January (average low 44.5°F). December is typically the wettest month (4.14 in) and July the driest (0.00 in).
Best time to visit Hillsborough
Full guide →Climate change signal
All-time records →73 of 366 (19.9%) of Hillsborough's all-time daily heat records have been set since 2015. If records were spread evenly across the station's history, only about 5% would fall in any given decade.
| 1940s | 14 | |
| 1950s | 56 | |
| 1960s | 33 | |
| 1970s | 39 | |
| 1980s | 51 | |
| 1990s | 33 | |
| 2000s | 45 | |
| 2010s | 54 | |
| 2020s | 41 |
Bars: number of all-time daily heat records still standing that were set in each decade.
Monthly averages
| Month | Avg High | Avg Low | Avg Temp | Precipitation | Snow | Rainy days |
|---|---|---|---|---|---|---|
| January | 58.0°F | 44.5°F | 51.3°F | 3.89 in | — | 11 |
| February | 60.8°F | 46.1°F | 53.5°F | 3.96 in | — | 11 |
| March | 63.4°F | 47.6°F | 55.5°F | 2.73 in | — | 10 |
| April | 65.6°F | 49.1°F | 57.3°F | 1.36 in | — | 6 |
| May | 68.3°F | 51.6°F | 59.9°F | 0.48 in | — | 3 |
| June | 71.5°F | 53.6°F | 62.5°F | 0.14 in | — | 1 |
| July | 72.6°F | 55.3°F | 64.0°F | 0.00 in | — | 0 |
| August | 73.4°F | 56.4°F | 64.9°F | 0.04 in | — | 0 |
| September | 74.8°F | 55.9°F | 65.3°F | 0.07 in | — | 1 |
| October | 72.3°F | 53.4°F | 62.9°F | 0.79 in | — | 3 |
| November | 64.3°F | 48.5°F | 56.4°F | 2.04 in | — | 7 |
| December | 58.2°F | 44.6°F | 51.4°F | 4.14 in | — | 11 |
Climate twins of Hillsborough
Why these? →The most climatically similar US cities at least 140 miles away (by monthly temperature + precipitation pattern).