Lamar, Nebraska has a Cold Semi-Arid Climate climate (Köppen classification: BSk). Average annual temperatures range from 2.3 °C (low) to 17.9 °C (high). Annual precipitation averages 440.4 Millimeters. Lamar 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 | -9.3 °C | 5.3 °C | 7.11 mm |
| February | -8.3 °C | 6.4 °C | 9.4 mm |
| March | -3.9 °C | 12.3 °C | 19.56 mm |
| April | 0.8 °C | 16.7 °C | 46.48 mm |
| May | 7.2 °C | 21.9 °C | 74.17 mm |
| June | 13.1 °C | 28.3 °C | 65.28 mm |
| July | 15.9 °C | 31.4 °C | 71.63 mm |
| August | 14.6 °C | 30.3 °C | 64.77 mm |
| September | 9.2 °C | 26.3 °C | 30.48 mm |
| October | 1.7 °C | 18.6 °C | 33.78 mm |
| November | -4.7 °C | 11.4 °C | 10.16 mm |
| December | -8.9 °C | 5.6 °C | 7.62 mm |
| Annual | 2.3 °C | 17.9 °C | 440.44 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 5b : -26.1°C to -23.3°C |
| Current Drought Conditions | Moderate Drought |
| Köppen Climate Classification | BSk - Cold Semi-Arid Climate |