Ammon, Idaho has a Cold Semi-Arid Climate climate (Köppen classification: BSk). Average annual temperatures range from 31.5 °F (low) to 57.3 °F (high). Annual precipitation averages 12.5 Inches. Ammon is located in USDA Plant Hardiness Zone 5b. The growing season typically runs from the last frost around May 21 - May 31 through the first frost around Sep.11 - Sep. 20.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 12.5 °F | 29.2 °F | 1.14 in. |
| February | 15.8 °F | 34.1 °F | 0.82 in. |
| March | 25.2 °F | 46.9 °F | 1.1 in. |
| April | 31.2 °F | 57.1 °F | 1.2 in. |
| May | 38.9 °F | 66.4 °F | 1.74 in. |
| June | 45.4 °F | 75.2 °F | 1.23 in. |
| July | 50.9 °F | 85.6 °F | 0.54 in. |
| August | 49.0 °F | 85.0 °F | 0.64 in. |
| September | 41.5 °F | 74.5 °F | 1.02 in. |
| October | 31.7 °F | 59.8 °F | 1.17 in. |
| November | 22.4 °F | 43.3 °F | 0.88 in. |
| December | 13.9 °F | 30.6 °F | 0.99 in. |
| Annual | 31.5 °F | 57.3 °F | 12.47 in. |
| Average First Frost Date | Sep.11 - Sep. 20 |
| Average Last Frost Date | May 21 - May 31 |
| Average Days With Frost | Over 180 Days |
| Plant Hardiness Zone | Zone 5b : -15°F to -10°F |
| Plant Hardiness Zone - 2012 | Zone 5a : -20°F to -15°F |
| Current Drought Conditions | Extreme Drought |
| Köppen Climate Classification | BSk - Cold Semi-Arid Climate |