Riverdale, California has a Cold Semi-Arid Climate climate (Köppen classification: BSk). Average annual temperatures range from 9.5 °C (low) to 25 °C (high). Annual precipitation averages 213.1 Millimeters. Riverdale is located in USDA Plant Hardiness Zone 9a. The growing season typically runs from the last frost around Feb. 21 - Feb. 29 through the first frost around Nov. 21 - Nov. 30.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 3.1 °C | 13.4 °C | 45.72 mm |
| February | 4.6 °C | 16.8 °C | 38.1 mm |
| March | 6.2 °C | 20.3 °C | 37.08 mm |
| April | 7.9 °C | 23.8 °C | 17.53 mm |
| May | 11.7 °C | 28.3 °C | 10.92 mm |
| June | 14.6 °C | 32.7 °C | 1.52 mm |
| July | 17.6 °C | 35.9 °C | 0.25 mm |
| August | 16.9 °C | 35.5 °C | 0 mm |
| September | 14.3 °C | 32.8 °C | 1.52 mm |
| October | 10 °C | 27.1 °C | 9.91 mm |
| November | 5.1 °C | 19.4 °C | 16.76 mm |
| December | 2.2 °C | 13.7 °C | 33.78 mm |
| Annual | 9.5 °C | 25 °C | 213.09 mm |
| Average First Frost Date | Nov. 21 - Nov. 30 |
| Average Last Frost Date | Feb. 21 - Feb. 29 |
| Average Days With Frost | 20-30 Days |
| Plant Hardiness Zone | Zone 9a : -6.7°C to -3.9°C |
| Plant Hardiness Zone - 2012 | Zone 9a : -6.7°C to -3.9°C |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | BSk - Cold Semi-Arid Climate |