Merriman, Nebraska has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 1.4 °C (low) to 16 °C (high). Annual precipitation averages 499.6 Millimeters. Merriman is located in USDA Plant Hardiness Zone 5a. 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 | -10.4 °C | 2.2 °C | 9.65 mm |
| February | -9.4 °C | 3.9 °C | 13.97 mm |
| March | -4.6 °C | 9.7 °C | 23.37 mm |
| April | 0 °C | 14.6 °C | 54.1 mm |
| May | 5.9 °C | 20.3 °C | 77.22 mm |
| June | 11.7 °C | 26.4 °C | 98.04 mm |
| July | 15.1 °C | 30.8 °C | 64.01 mm |
| August | 13.8 °C | 30 °C | 54.1 mm |
| September | 8.4 °C | 25.5 °C | 39.62 mm |
| October | 1.2 °C | 16.9 °C | 39.88 mm |
| November | -5.1 °C | 9.2 °C | 14.99 mm |
| December | -9.7 °C | 3 °C | 10.67 mm |
| Annual | 1.4 °C | 16 °C | 499.62 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 5a : -28.9°C to -26.1°C |
| Plant Hardiness Zone - 2012 | Zone 4b : -31.7°C to -28.9°C |
| Current Drought Conditions | Moderate Drought |
| Köppen Climate Classification | Dfa - Humid Continental Hot Summers With Year Around Precipitation |