Sweetwater, Idaho has a Hot-Summer Mediterranean Climate climate (Köppen classification: Csa). Average annual temperatures range from 41.1 °F (low) to 64 °F (high). Annual precipitation averages 19.6 Inches. Sweetwater is located in USDA Plant Hardiness Zone 7b. The growing season typically runs from the last frost around Apr. 11 - Apr. 20 through the first frost around Oct. 11 - Oct. 20.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 29.2 °F | 41.0 °F | 1.98 in. |
| February | 30.1 °F | 46.6 °F | 1.74 in. |
| March | 33.9 °F | 55.0 °F | 2.0 in. |
| April | 39.0 °F | 62.7 °F | 2.08 in. |
| May | 45.6 °F | 71.9 °F | 2.01 in. |
| June | 51.4 °F | 78.5 °F | 1.56 in. |
| July | 56.2 °F | 90.4 °F | 0.77 in. |
| August | 55.8 °F | 90.5 °F | 0.68 in. |
| September | 48.9 °F | 80.1 °F | 0.81 in. |
| October | 40.3 °F | 63.4 °F | 1.74 in. |
| November | 33.8 °F | 48.5 °F | 2.18 in. |
| December | 28.5 °F | 39.6 °F | 2.09 in. |
| Annual | 41.1 °F | 64 °F | 19.64 in. |
| Average First Frost Date | Oct. 11 - Oct. 20 |
| Average Last Frost Date | Apr. 11 - Apr. 20 |
| Average Days With Frost | 75-100 Days |
| Plant Hardiness Zone | Zone 7b : 5°F to 10°F |
| Plant Hardiness Zone - 2012 | Zone 7a : 0°F to 5°F |
| Current Drought Conditions | Moderate Drought |
| Köppen Climate Classification | Csa - Hot-Summer Mediterranean Climate |