Tennant, California has a Humid Continental Climate - Dry Cool Summer climate (Köppen classification: Dsb). Average annual temperatures range from 1.4 °C (low) to 15.7 °C (high). Annual precipitation averages 619.3 Millimeters. Tennant is located in USDA Plant Hardiness Zone 7a. The growing season typically runs from the last frost around Jun. 11 - Jun. 20 through the first frost around Sep.1 - Sep. 10.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -4.8 °C | 5.2 °C | 107.7 mm |
| February | -4.4 °C | 6.9 °C | 93.98 mm |
| March | -2.8 °C | 9.6 °C | 84.58 mm |
| April | -1.3 °C | 12.8 °C | 45.21 mm |
| May | 2.4 °C | 17.9 °C | 40.13 mm |
| June | 6 °C | 23.1 °C | 20.32 mm |
| July | 10.8 °C | 28.8 °C | 7.37 mm |
| August | 10.1 °C | 28.4 °C | 7.62 mm |
| September | 6.6 °C | 24.5 °C | 12.7 mm |
| October | 1.9 °C | 17.1 °C | 33.27 mm |
| November | -2.6 °C | 9.1 °C | 64.77 mm |
| December | -5.4 °C | 4.5 °C | 101.6 mm |
| Annual | 1.4 °C | 15.7 °C | 619.25 mm |
| Average First Frost Date | Sep.1 - Sep. 10 |
| Average Last Frost Date | Jun. 11 - Jun. 20 |
| Average Days With Frost | 125-150 Days |
| Plant Hardiness Zone | Zone 7a : -17.8°C to -15°C |
| Plant Hardiness Zone - 2012 | Zone 7a : -17.8°C to -15°C |
| Current Drought Conditions | Abnormally Dry |
| Köppen Climate Classification | Dsb - Humid Continental Climate - Dry Cool Summer |