Sweetwater, Idaho has a Hot-Summer Mediterranean Climate climate (Köppen classification: Csa). Average annual temperatures range from 5 °C (low) to 17.8 °C (high). Annual precipitation averages 498.9 Millimeters. 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 | -1.6 °C | 5 °C | 50.29 mm |
| February | -1.1 °C | 8.1 °C | 44.2 mm |
| March | 1.1 °C | 12.8 °C | 50.8 mm |
| April | 3.9 °C | 17.1 °C | 52.83 mm |
| May | 7.6 °C | 22.2 °C | 51.05 mm |
| June | 10.8 °C | 25.8 °C | 39.62 mm |
| July | 13.4 °C | 32.4 °C | 19.56 mm |
| August | 13.2 °C | 32.5 °C | 17.27 mm |
| September | 9.4 °C | 26.7 °C | 20.57 mm |
| October | 4.6 °C | 17.4 °C | 44.2 mm |
| November | 1 °C | 9.2 °C | 55.37 mm |
| December | -1.9 °C | 4.2 °C | 53.09 mm |
| Annual | 5 °C | 17.8 °C | 498.85 mm |
| 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 : -15°C to -12.2°C |
| Plant Hardiness Zone - 2012 | Zone 7a : -17.8°C to -15°C |
| Current Drought Conditions | Moderate Drought |
| Köppen Climate Classification | Csa - Hot-Summer Mediterranean Climate |