Rathdrum, Idaho has a Humid Continental Climate - Dry Cool Summer climate (Köppen classification: Dsb). Average annual temperatures range from 2.4 °C (low) to 14.5 °C (high). Annual precipitation averages 651.3 Millimeters. Rathdrum is located in USDA Plant Hardiness Zone 6b. The growing season typically runs from the last frost around Apr. 21 - Apr. 30 through the first frost around Oct. 1 - Oct. 10.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -4.2 °C | 2.1 °C | 85.09 mm |
| February | -4.2 °C | 4.4 °C | 53.85 mm |
| March | -1.7 °C | 9.1 °C | 66.29 mm |
| April | 1.1 °C | 13.6 °C | 52.58 mm |
| May | 5.2 °C | 19.1 °C | 53.59 mm |
| June | 8.4 °C | 22.4 °C | 50.8 mm |
| July | 11.1 °C | 28.4 °C | 17.53 mm |
| August | 10.7 °C | 28.8 °C | 18.54 mm |
| September | 6.6 °C | 23.2 °C | 22.35 mm |
| October | 2 °C | 14.6 °C | 55.37 mm |
| November | -1.4 °C | 6.4 °C | 81.28 mm |
| December | -4.3 °C | 1.7 °C | 93.98 mm |
| Annual | 2.4 °C | 14.5 °C | 651.25 mm |
| Average First Frost Date | Oct. 1 - Oct. 10 |
| Average Last Frost Date | Apr. 21 - Apr. 30 |
| Average Days With Frost | 150-180 Days |
| Plant Hardiness Zone | Zone 6b : -20.6°C to -17.8°C |
| Plant Hardiness Zone - 2012 | Zone 6b : -20.6°C to -17.8°C |
| Current Drought Conditions | Severe Drought |
| Köppen Climate Classification | Dsb - Humid Continental Climate - Dry Cool Summer |