Lake Nacimiento, California has a Warm-Summer Mediterranean Climate climate (Köppen classification: Csb). Average annual temperatures range from 5.5 °C (low) to 25.4 °C (high). Annual precipitation averages 416.1 Millimeters. 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 | 1.4 °C | 16.8 °C | 95.76 mm |
| February | 2.2 °C | 17.7 °C | 92.2 mm |
| March | 3.4 °C | 20.1 °C | 64.26 mm |
| April | 4.1 °C | 22.7 °C | 25.15 mm |
| May | 6.3 °C | 27.1 °C | 8.89 mm |
| June | 8.6 °C | 31.7 °C | 1.78 mm |
| July | 10.9 °C | 34.8 °C | 1.52 mm |
| August | 10.7 °C | 35.3 °C | 0.51 mm |
| September | 9.1 °C | 33.1 °C | 1.27 mm |
| October | 6.2 °C | 27.8 °C | 18.54 mm |
| November | 2.8 °C | 21.1 °C | 36.58 mm |
| December | 0.8 °C | 16.4 °C | 69.6 mm |
| Annual | 5.5 °C | 25.4 °C | 416.06 mm |
| 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 : -6.7°C to -3.9°C |
| Plant Hardiness Zone - 2012 | Zone 8b : -9.4°C to -6.7°C |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Csb - Warm-Summer Mediterranean Climate |