Lake Nacimiento, California has a Warm-Summer Mediterranean Climate climate (Köppen classification: Csb). Average annual temperatures range from 42 °F (low) to 77.7 °F (high). Annual precipitation averages 16.4 Inches. Lake Nacimiento is located in USDA Plant Hardiness Zone 9a. The growing season typically runs from the last frost around Apr. 11 - Apr. 20 through the first frost around Oct. 21 - Oct. 31.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 34.6 °F | 62.3 °F | 3.77 in. |
| February | 36.0 °F | 63.8 °F | 3.63 in. |
| March | 38.2 °F | 68.1 °F | 2.53 in. |
| April | 39.3 °F | 72.9 °F | 0.99 in. |
| May | 43.3 °F | 80.8 °F | 0.35 in. |
| June | 47.4 °F | 89.1 °F | 0.07 in. |
| July | 51.7 °F | 94.7 °F | 0.06 in. |
| August | 51.3 °F | 95.6 °F | 0.02 in. |
| September | 48.4 °F | 91.5 °F | 0.05 in. |
| October | 43.1 °F | 82.1 °F | 0.73 in. |
| November | 37.1 °F | 69.9 °F | 1.44 in. |
| December | 33.4 °F | 61.6 °F | 2.74 in. |
| Annual | 42 °F | 77.7 °F | 16.38 in. |
| Average First Frost Date | Oct. 21 - Oct. 31 |
| Average Last Frost Date | Apr. 11 - Apr. 20 |
| Average Days With Frost | 50-75 Days |
| Plant Hardiness Zone | Zone 9a : 20°F to 25°F |
| Plant Hardiness Zone - 2012 | Zone 8b : 15°F to 20°F |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Csb - Warm-Summer Mediterranean Climate |