Rupert, Idaho has a Cold Semi-Arid Climate climate (Köppen classification: BSk). Average annual temperatures range from 34.7 °F (low) to 61.1 °F (high). Annual precipitation averages 10.3 Inches. Rupert is located in USDA Plant Hardiness Zone 6a. 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 | 18.8 °F | 36.0 °F | 1.21 in. |
| February | 21.8 °F | 41.3 °F | 0.7 in. |
| March | 28.0 °F | 51.7 °F | 1.0 in. |
| April | 32.7 °F | 59.1 °F | 1.04 in. |
| May | 40.7 °F | 68.7 °F | 1.43 in. |
| June | 47.3 °F | 77.6 °F | 0.74 in. |
| July | 53.8 °F | 87.9 °F | 0.24 in. |
| August | 51.8 °F | 87.0 °F | 0.4 in. |
| September | 43.5 °F | 77.0 °F | 0.59 in. |
| October | 34.0 °F | 63.2 °F | 0.85 in. |
| November | 25.2 °F | 47.8 °F | 0.88 in. |
| December | 18.9 °F | 36.4 °F | 1.25 in. |
| Annual | 34.7 °F | 61.1 °F | 10.33 in. |
| Average First Frost Date | Oct. 1 - Oct. 10 |
| Average Last Frost Date | May 1 - May 10 |
| Average Days With Frost | 150-180 Days |
| Plant Hardiness Zone | Zone 6a : -10°F to -5°F |
| Plant Hardiness Zone - 2012 | Zone 6a : -10°F to -5°F |
| Current Drought Conditions | Extreme Drought |
| Köppen Climate Classification | BSk - Cold Semi-Arid Climate |