Los Osos, California has a Warm-Summer Mediterranean Climate climate (Köppen classification: Csb). Average annual temperatures range from 48.3 °F (low) to 65.4 °F (high). Annual precipitation averages 17.5 Inches. Los Osos is located in USDA Plant Hardiness Zone 10a.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 43.6 °F | 63.5 °F | 3.57 in. |
| February | 44.2 °F | 63.5 °F | 3.89 in. |
| March | 45.4 °F | 64.6 °F | 3.25 in. |
| April | 46.0 °F | 63.9 °F | 1.11 in. |
| May | 48.5 °F | 63.2 °F | 0.45 in. |
| June | 51.0 °F | 64.8 °F | 0.05 in. |
| July | 53.8 °F | 66.0 °F | 0.09 in. |
| August | 54.1 °F | 66.6 °F | 0.04 in. |
| September | 53.2 °F | 67.8 °F | 0.12 in. |
| October | 51.1 °F | 69.3 °F | 0.63 in. |
| November | 46.6 °F | 68.1 °F | 1.3 in. |
| December | 42.6 °F | 63.2 °F | 3.01 in. |
| Annual | 48.3 °F | 65.4 °F | 17.51 in. |
| Average First Frost Date | No Frost |
| Average Last Frost Date | |
| Average Days With Frost | Frost Rare |
| Plant Hardiness Zone | Zone 10a : 30°F to 25°F |
| Plant Hardiness Zone - 2012 | Zone 10a : 30°F to 25°F |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Csb - Warm-Summer Mediterranean Climate |