Truro, Iowa has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 4.2 °C (low) to 15.8 °C (high). Annual precipitation averages 928.1 Millimeters. Truro is located in USDA Plant Hardiness Zone 5b. The growing season typically runs from the last frost around Apr. 21 - Apr. 30 through the first frost around Oct. 1 - Oct. 10.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -10.7 °C | -0.5 °C | 24.13 mm |
| February | -8.4 °C | 2.2 °C | 32.77 mm |
| March | -2.6 °C | 9.3 °C | 53.85 mm |
| April | 3.7 °C | 16.4 °C | 96.01 mm |
| May | 10.3 °C | 21.9 °C | 134.11 mm |
| June | 15.9 °C | 27.2 °C | 126.75 mm |
| July | 18.2 °C | 29.6 °C | 108.71 mm |
| August | 16.8 °C | 28.7 °C | 103.63 mm |
| September | 11.8 °C | 24.8 °C | 93.98 mm |
| October | 5.1 °C | 17.8 °C | 67.82 mm |
| November | -1.7 °C | 9.4 °C | 50.8 mm |
| December | -7.6 °C | 2.2 °C | 35.56 mm |
| Annual | 4.2 °C | 15.8 °C | 928.12 mm |
| Average First Frost Date | Oct. 1 - Oct. 10 |
| Average Last Frost Date | Apr. 21 - Apr. 30 |
| Average Days With Frost | 125-150 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 | Normal |
| Köppen Climate Classification | Dfa - Humid Continental Hot Summers With Year Around Precipitation |