McGrew, Nebraska has a Cold Semi-Arid Climate climate (Köppen classification: BSk). Average annual temperatures range from 1.5 °C (low) to 17.8 °C (high). Annual precipitation averages 393.5 Millimeters. McGrew 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 | -9.9 °C | 4.7 °C | 7.11 mm |
| February | -8.6 °C | 6.4 °C | 10.92 mm |
| March | -4.1 °C | 11.9 °C | 19.81 mm |
| April | 0.3 °C | 16.3 °C | 43.69 mm |
| May | 6.2 °C | 21.7 °C | 73.41 mm |
| June | 11.8 °C | 28.3 °C | 69.09 mm |
| July | 15.2 °C | 32.3 °C | 45.72 mm |
| August | 13.9 °C | 31.3 °C | 36.32 mm |
| September | 8.2 °C | 26.4 °C | 36.58 mm |
| October | 0.7 °C | 18.2 °C | 28.45 mm |
| November | -5.5 °C | 10.7 °C | 12.45 mm |
| December | -10.2 °C | 4.8 °C | 9.91 mm |
| Annual | 1.5 °C | 17.8 °C | 393.46 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 5a : -28.9°C to -26.1°C |
| Current Drought Conditions | Extreme Drought |
| Köppen Climate Classification | BSk - Cold Semi-Arid Climate |