Plymouth, Nebraska has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 4.8 °C (low) to 17.3 °C (high). Annual precipitation averages 782.1 Millimeters. Plymouth is located in USDA Plant Hardiness Zone 6a. 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 | -9.3 °C | 1.8 °C | 18.29 mm |
| February | -7.2 °C | 4.4 °C | 22.61 mm |
| March | -1.9 °C | 11.2 °C | 41.66 mm |
| April | 3.8 °C | 17.3 °C | 72.39 mm |
| May | 10.4 °C | 23.1 °C | 126.24 mm |
| June | 16.4 °C | 28.6 °C | 114.3 mm |
| July | 18.7 °C | 30.9 °C | 102.87 mm |
| August | 17.4 °C | 30.1 °C | 86.36 mm |
| September | 12.4 °C | 26.2 °C | 77.47 mm |
| October | 5.3 °C | 19.2 °C | 58.17 mm |
| November | -1.7 °C | 10.9 °C | 34.8 mm |
| December | -7.1 °C | 4.1 °C | 26.92 mm |
| Annual | 4.8 °C | 17.3 °C | 782.08 mm |
| Average First Frost Date | Oct. 11 - Oct. 20 |
| Average Last Frost Date | Apr. 11 - Apr. 20 |
| Average Days With Frost | 125-150 Days |
| Plant Hardiness Zone | Zone 6a : -23.3°C to -20.6°C |
| Plant Hardiness Zone - 2012 | Zone 5b : -26.1°C to -23.3°C |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Dfa - Humid Continental Hot Summers With Year Around Precipitation |