Rexburg, Idaho has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from -1.1 °C (low) to 13.4 °C (high). Annual precipitation averages 311.4 Millimeters. Rexburg is located in USDA Plant Hardiness Zone 5a. The growing season typically runs from the last frost around May 11 - May 20 through the first frost around Sep.11 - Sep. 20.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -11.9 °C | -2.1 °C | 27.43 mm |
| February | -10 °C | 0.5 °C | 17.78 mm |
| March | -4.8 °C | 7.3 °C | 23.88 mm |
| April | -1.1 °C | 13.4 °C | 28.7 mm |
| May | 3.2 °C | 18.6 °C | 43.69 mm |
| June | 6.7 °C | 23.3 °C | 35.56 mm |
| July | 9.7 °C | 29 °C | 13.97 mm |
| August | 8.6 °C | 28.8 °C | 17.78 mm |
| September | 4.4 °C | 22.9 °C | 25.15 mm |
| October | -0.9 °C | 14.7 °C | 29.46 mm |
| November | -6 °C | 5.7 °C | 22.1 mm |
| December | -10.9 °C | -1.3 °C | 25.91 mm |
| Annual | -1.1 °C | 13.4 °C | 311.41 mm |
| Average First Frost Date | Sep.11 - Sep. 20 |
| Average Last Frost Date | May 11 - May 20 |
| Average Days With Frost | 150-180 Days |
| Plant Hardiness Zone | Zone 5a : -28.9°C to -26.1°C |
| Plant Hardiness Zone - 2012 | Zone 5a : -28.9°C to -26.1°C |
| Current Drought Conditions | Extreme Drought |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |