Philo, California has a Warm-Summer Mediterranean Climate climate (Köppen classification: Csb). Average annual temperatures range from 7.7 °C (low) to 21.5 °C (high). Annual precipitation averages 1033 Millimeters. Philo is located in USDA Plant Hardiness Zone 9b. The growing season typically runs from the last frost around Mar. 1 - Mar. 10 through the first frost around Dec. 1 - Dec. 10.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 4.6 °C | 14 °C | 206.25 mm |
| February | 4.7 °C | 14.8 °C | 166.12 mm |
| March | 5.6 °C | 16.2 °C | 141.48 mm |
| April | 6.6 °C | 20.1 °C | 80.01 mm |
| May | 8.6 °C | 23.1 °C | 39.88 mm |
| June | 10.5 °C | 26.6 °C | 8.13 mm |
| July | 11.3 °C | 29.7 °C | 0.76 mm |
| August | 11.5 °C | 29.6 °C | 1.78 mm |
| September | 10.6 °C | 28.8 °C | 3.56 mm |
| October | 8.5 °C | 24.4 °C | 45.21 mm |
| November | 5.9 °C | 16.9 °C | 107.44 mm |
| December | 4.2 °C | 14.2 °C | 232.41 mm |
| Annual | 7.7 °C | 21.5 °C | 1033.03 mm |
| Average First Frost Date | Dec. 1 - Dec. 10 |
| Average Last Frost Date | Mar. 1 - Mar. 10 |
| Average Days With Frost | 10-20 Days |
| Plant Hardiness Zone | Zone 9b : -3.9°C to -1.1°C |
| Plant Hardiness Zone - 2012 | Zone 9b : -3.9°C to -1.1°C |
| Current Drought Conditions | Abnormally Dry |
| Köppen Climate Classification | Csb - Warm-Summer Mediterranean Climate |