Weather information for the Santa Rosa area is provided below. Average temperatures, climate details and current forecasts are included.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | ||
| Avg. High | 54 | 59 | 66 | 74 | 82 | 90 | 92 | 90 | 84 | 75 | 62 | 54 | |
| Avg. Low | 21 | 25 | 30 | 36 | 45 | 54 | 58 | 56 | 49 | 38 | 28 | 22 | |
| Precipitation | 0.4 | 0.4 | 0.7 | 0.9 | 1.4 | 1.8 | 2.4 | 2.9 | 1.9 | 1.2 | 0.9 | 0.7 | |


