Heyburn, Idaho has a Cold Semi-Arid Climate climate (Köppen classification: BSk). Average annual temperatures range from 1.7 °C (low) to 16.2 °C (high). Annual precipitation averages 263.4 Millimeters. Heyburn is located in USDA Plant Hardiness Zone 6b. The growing season typically runs from the last frost around May 1 - May 10 through the first frost around Oct. 1 - Oct. 10.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -7.1 °C | 2.3 °C | 30.48 mm |
| February | -5.3 °C | 5.3 °C | 17.27 mm |
| March | -2 °C | 11.1 °C | 25.4 mm |
| April | 0.6 °C | 15.1 °C | 26.42 mm |
| May | 5 °C | 20.3 °C | 37.08 mm |
| June | 8.7 °C | 25.3 °C | 19.05 mm |
| July | 12.3 °C | 31.1 °C | 6.1 mm |
| August | 11.2 °C | 30.6 °C | 10.41 mm |
| September | 6.6 °C | 25 °C | 14.99 mm |
| October | 1.3 °C | 17.3 °C | 21.34 mm |
| November | -3.7 °C | 8.8 °C | 22.1 mm |
| December | -7 °C | 2.6 °C | 32.77 mm |
| Annual | 1.7 °C | 16.2 °C | 263.41 mm |
| Average First Frost Date | Oct. 1 - Oct. 10 |
| Average Last Frost Date | May 1 - May 10 |
| Average Days With Frost | 125-150 Days |
| Plant Hardiness Zone | Zone 6b : -20.6°C to -17.8°C |
| Plant Hardiness Zone - 2012 | Zone 6a : -23.3°C to -20.6°C |
| Current Drought Conditions | Extreme Drought |
| Köppen Climate Classification | BSk - Cold Semi-Arid Climate |