Los Osos, California has a Warm-Summer Mediterranean Climate climate (Köppen classification: Csb). Average annual temperatures range from 9.1 °C (low) to 18.5 °C (high). Annual precipitation averages 444.8 Millimeters. Los Osos is located in USDA Plant Hardiness Zone 10a.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 6.4 °C | 17.5 °C | 90.68 mm |
| February | 6.8 °C | 17.5 °C | 98.81 mm |
| March | 7.4 °C | 18.1 °C | 82.55 mm |
| April | 7.8 °C | 17.7 °C | 28.19 mm |
| May | 9.2 °C | 17.3 °C | 11.43 mm |
| June | 10.6 °C | 18.2 °C | 1.27 mm |
| July | 12.1 °C | 18.9 °C | 2.29 mm |
| August | 12.3 °C | 19.2 °C | 1.02 mm |
| September | 11.8 °C | 19.9 °C | 3.05 mm |
| October | 10.6 °C | 20.7 °C | 16 mm |
| November | 8.1 °C | 20.1 °C | 33.02 mm |
| December | 5.9 °C | 17.3 °C | 76.45 mm |
| Annual | 9.1 °C | 18.5 °C | 444.76 mm |
| Average First Frost Date | No Frost |
| Average Last Frost Date | |
| Average Days With Frost | Frost Rare |
| Plant Hardiness Zone | Zone 10a : -1.1°C to 1.7°C |
| Plant Hardiness Zone - 2012 | Zone 10a : -1.1°C to 1.7°C |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Csb - Warm-Summer Mediterranean Climate |