Montague, California has a Warm-Summer Mediterranean Climate climate (Köppen classification: Csb). Average annual temperatures range from 3.3 °C (low) to 19.7 °C (high). Annual precipitation averages 414.8 Millimeters. Montague is located in USDA Plant Hardiness Zone 8a. The growing season typically runs from the last frost around May 1 - May 10 through the first frost around Oct. 11 - Oct. 20.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -2.7 °C | 8.1 °C | 66.04 mm |
| February | -1.9 °C | 10.9 °C | 48.01 mm |
| March | -0.4 °C | 14 °C | 37.59 mm |
| April | 1.6 °C | 17.3 °C | 29.46 mm |
| May | 5.1 °C | 22.7 °C | 30.23 mm |
| June | 8.1 °C | 27.6 °C | 17.27 mm |
| July | 11.9 °C | 33.4 °C | 10.41 mm |
| August | 11.2 °C | 33 °C | 8.64 mm |
| September | 7.6 °C | 28.9 °C | 8.38 mm |
| October | 2.7 °C | 20.9 °C | 27.18 mm |
| November | -0.8 °C | 12.1 °C | 51.05 mm |
| December | -2.8 °C | 7.3 °C | 80.52 mm |
| Annual | 3.3 °C | 19.7 °C | 414.78 mm |
| Average First Frost Date | Oct. 11 - Oct. 20 |
| Average Last Frost Date | May 1 - May 10 |
| Average Days With Frost | 100-125 Days |
| Plant Hardiness Zone | Zone 8a : -12.2°C to -9.4°C |
| Plant Hardiness Zone - 2012 | Zone 7b : -15°C to -12.2°C |
| Current Drought Conditions | Abnormally Dry |
| Köppen Climate Classification | Csb - Warm-Summer Mediterranean Climate |