Monte Sereno, California has a Warm-Summer Mediterranean Climate climate (Köppen classification: Csb). Average annual temperatures range from 46.7 °F (low) to 72.4 °F (high). Annual precipitation averages 28.5 Inches. Monte Sereno is located in USDA Plant Hardiness Zone 9b. The growing season typically runs from the last frost around Jan. 21 - Jan. 31 through the first frost around Jan. 1 - Jan. 10.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 39.6 °F | 60.0 °F | 6.38 in. |
| February | 40.9 °F | 62.1 °F | 5.43 in. |
| March | 42.9 °F | 65.9 °F | 4.38 in. |
| April | 44.7 °F | 69.4 °F | 1.93 in. |
| May | 48.4 °F | 74.9 °F | 0.61 in. |
| June | 51.5 °F | 81.4 °F | 0.12 in. |
| July | 54.3 °F | 84.8 °F | 0.0 in. |
| August | 54.3 °F | 84.7 °F | 0.04 in. |
| September | 52.8 °F | 83.2 °F | 0.07 in. |
| October | 48.6 °F | 76.8 °F | 0.87 in. |
| November | 43.0 °F | 66.3 °F | 2.41 in. |
| December | 39.5 °F | 59.1 °F | 6.27 in. |
| Annual | 46.7 °F | 72.4 °F | 28.51 in. |
| Average First Frost Date | Jan. 1 - Jan. 10 |
| Average Last Frost Date | Jan. 21 - Jan. 31 |
| Average Days With Frost | 10-20 Days |
| Plant Hardiness Zone | Zone 9b : 25°F to 20°F |
| Plant Hardiness Zone - 2012 | Zone 9b : 25°F to 20°F |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Csb - Warm-Summer Mediterranean Climate |