Long Grove, Iowa has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 4.3 °C (low) to 15.1 °C (high). Annual precipitation averages 983.5 Millimeters. Long Grove is located in USDA Plant Hardiness Zone 5b. The growing season typically runs from the last frost around Apr. 11 - Apr. 20 through the first frost around Oct. 21 - Oct. 31.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -10.5 °C | -1.5 °C | 37.08 mm |
| February | -8.6 °C | 0.9 °C | 47.75 mm |
| March | -2.5 °C | 8.2 °C | 64.77 mm |
| April | 3.7 °C | 15.8 °C | 99.31 mm |
| May | 10.3 °C | 21.9 °C | 125.48 mm |
| June | 15.9 °C | 26.9 °C | 124.46 mm |
| July | 17.9 °C | 28.6 °C | 108.97 mm |
| August | 16.6 °C | 27.6 °C | 104.14 mm |
| September | 12.1 °C | 24.7 °C | 91.69 mm |
| October | 5.4 °C | 17.2 °C | 72.14 mm |
| November | -1.2 °C | 8.9 °C | 56.9 mm |
| December | -7.1 °C | 1.6 °C | 50.8 mm |
| Annual | 4.3 °C | 15.1 °C | 983.49 mm |
| Average First Frost Date | Oct. 21 - Oct. 31 |
| Average Last Frost Date | Apr. 11 - Apr. 20 |
| Average Days With Frost | 100-125 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 | Normal |
| Köppen Climate Classification | Dfa - Humid Continental Hot Summers With Year Around Precipitation |