Mullen, Nebraska has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 1.9 °C (low) to 16.3 °C (high). Annual precipitation averages 609.1 Millimeters. Mullen is located in USDA Plant Hardiness Zone 5b. 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 | -9.9 °C | 3.1 °C | 8.64 mm |
| February | -9 °C | 4.3 °C | 15.24 mm |
| March | -4.3 °C | 10.2 °C | 31.75 mm |
| April | 0.6 °C | 15.1 °C | 65.53 mm |
| May | 6.6 °C | 20.8 °C | 98.3 mm |
| June | 12.3 °C | 27.1 °C | 101.6 mm |
| July | 15.5 °C | 30.7 °C | 99.82 mm |
| August | 14.2 °C | 29.6 °C | 69.09 mm |
| September | 8.8 °C | 24.8 °C | 49.53 mm |
| October | 1.6 °C | 17.2 °C | 41.66 mm |
| November | -4.6 °C | 9.6 °C | 17.02 mm |
| December | -9.2 °C | 3.6 °C | 10.92 mm |
| Annual | 1.9 °C | 16.3 °C | 609.1 mm |
| 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 5b : -26.1°C to -23.3°C |
| Plant Hardiness Zone - 2012 | Zone 5a : -28.9°C to -26.1°C |
| Current Drought Conditions | Extreme Drought |
| Köppen Climate Classification | Dfa - Humid Continental Hot Summers With Year Around Precipitation |