Jerome, Idaho has a Cold Semi-Arid Climate climate (Köppen classification: BSk). Average annual temperatures range from 2.9 °C (low) to 16.9 °C (high). Annual precipitation averages 264.7 Millimeters. Jerome is located in USDA Plant Hardiness Zone 6b. The growing season typically runs from the last frost around May 11 - May 20 through the first frost around Oct. 1 - Oct. 10.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -6.1 °C | 2.7 °C | 33.27 mm |
| February | -4.5 °C | 5.7 °C | 19.56 mm |
| March | -1.2 °C | 11.6 °C | 26.92 mm |
| April | 1.6 °C | 15.7 °C | 26.42 mm |
| May | 6 °C | 21.1 °C | 32.77 mm |
| June | 10 °C | 26.4 °C | 16 mm |
| July | 14 °C | 32.3 °C | 3.3 mm |
| August | 12.8 °C | 31.4 °C | 6.86 mm |
| September | 8.2 °C | 25.8 °C | 10.92 mm |
| October | 2.6 °C | 17.9 °C | 22.86 mm |
| November | -2.5 °C | 9.3 °C | 26.42 mm |
| December | -6 °C | 2.7 °C | 39.37 mm |
| Annual | 2.9 °C | 16.9 °C | 264.67 mm |
| Average First Frost Date | Oct. 1 - Oct. 10 |
| Average Last Frost Date | May 11 - May 20 |
| Average Days With Frost | 150-180 Days |
| Plant Hardiness Zone | Zone 6b : -20.6°C to -17.8°C |
| Plant Hardiness Zone - 2012 | Zone 6b : -20.6°C to -17.8°C |
| Current Drought Conditions | Extreme Drought |
| Köppen Climate Classification | BSk - Cold Semi-Arid Climate |