Troy, Indiana has a Humid Subtropical Climate climate (Köppen classification: Cfa). Average annual temperatures range from 8.2 °C (low) to 19.5 °C (high). Annual precipitation averages 1285.8 Millimeters. Troy is located in USDA Plant Hardiness Zone 7a. The growing season typically runs from the last frost around Mar. 21 - Mar. 31 through the first frost around Nov. 1 - Nov. 10.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -3.5 °C | 5.8 °C | 92.46 mm |
| February | -2.2 °C | 8.4 °C | 90.17 mm |
| March | 2.1 °C | 13.7 °C | 117.86 mm |
| April | 7.6 °C | 20 °C | 129.54 mm |
| May | 13.3 °C | 24.9 °C | 143.26 mm |
| June | 17.9 °C | 29.3 °C | 123.44 mm |
| July | 19.9 °C | 30.9 °C | 109.98 mm |
| August | 18.9 °C | 30.6 °C | 78.99 mm |
| September | 14.8 °C | 27.5 °C | 92.96 mm |
| October | 8.3 °C | 21.3 °C | 96.77 mm |
| November | 2.7 °C | 13.8 °C | 100.08 mm |
| December | -1.3 °C | 8.1 °C | 110.24 mm |
| Annual | 8.2 °C | 19.5 °C | 1285.75 mm |
| Average First Frost Date | Nov. 1 - Nov. 10 |
| Average Last Frost Date | Mar. 21 - Mar. 31 |
| Average Days With Frost | 50-75 Days |
| Plant Hardiness Zone | Zone 7a : -17.8°C to -15°C |
| Plant Hardiness Zone - 2012 | Zone 6b : -20.6°C to -17.8°C |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Cfa - Humid Subtropical Climate |