Sidney, Iowa has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 5 °C (low) to 16.4 °C (high). Annual precipitation averages 852.4 Millimeters. Sidney is located in USDA Plant Hardiness Zone 6a. The growing season typically runs from the last frost around Apr. 21 - Apr. 30 through the first frost around Oct. 11 - Oct. 20.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -9.7 °C | 0.4 °C | 18.8 mm |
| February | -7.4 °C | 3.3 °C | 27.18 mm |
| March | -1.6 °C | 10.5 °C | 45.72 mm |
| April | 4.3 °C | 16.9 °C | 84.07 mm |
| May | 10.8 °C | 22.6 °C | 134.87 mm |
| June | 16.6 °C | 27.7 °C | 125.98 mm |
| July | 18.8 °C | 29.7 °C | 109.73 mm |
| August | 17.6 °C | 28.8 °C | 89.92 mm |
| September | 12.3 °C | 25.4 °C | 76.45 mm |
| October | 5.9 °C | 18.8 °C | 68.33 mm |
| November | -1.2 °C | 10 °C | 40.39 mm |
| December | -6.8 °C | 3 °C | 30.99 mm |
| Annual | 5 °C | 16.4 °C | 852.43 mm |
| Average First Frost Date | Oct. 11 - Oct. 20 |
| Average Last Frost Date | Apr. 21 - Apr. 30 |
| 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 |