Smithfield, Nebraska has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 3.3 °C (low) to 17.5 °C (high). Annual precipitation averages 606.3 Millimeters. Smithfield 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 | -9.6 °C | 3.2 °C | 10.67 mm |
| February | -7.7 °C | 5.2 °C | 16.51 mm |
| March | -3.4 °C | 11.5 °C | 32.26 mm |
| April | 2.5 °C | 16.6 °C | 60.71 mm |
| May | 8.5 °C | 22.5 °C | 94.23 mm |
| June | 14.6 °C | 28.7 °C | 90.68 mm |
| July | 17 °C | 31.3 °C | 95 mm |
| August | 15.8 °C | 29.7 °C | 79.25 mm |
| September | 10.6 °C | 26.3 °C | 43.94 mm |
| October | 3.3 °C | 19.2 °C | 45.21 mm |
| November | -3.6 °C | 10.9 °C | 21.59 mm |
| December | -8.6 °C | 4.5 °C | 16.26 mm |
| Annual | 3.3 °C | 17.5 °C | 606.31 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 | Severe Drought |
| Köppen Climate Classification | Dfa - Humid Continental Hot Summers With Year Around Precipitation |