Loretto, Tennessee has a Humid Subtropical Climate climate (Köppen classification: Cfa). Average annual temperatures range from 8.8 °C (low) to 21.4 °C (high). Annual precipitation averages 1530.6 Millimeters. Loretto is located in USDA Plant Hardiness Zone 7b. The growing season typically runs from the last frost around Apr. 1 - Apr. 10 through the first frost around Oct. 21 - Oct. 31.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -1.8 °C | 9.6 °C | 133.6 mm |
| February | -0.2 °C | 12 °C | 141.99 mm |
| March | 3.6 °C | 16.8 °C | 151.64 mm |
| April | 8.1 °C | 21.9 °C | 142.49 mm |
| May | 13.3 °C | 25.9 °C | 129.54 mm |
| June | 17.7 °C | 29.7 °C | 117.35 mm |
| July | 19.7 °C | 31.4 °C | 125.48 mm |
| August | 18.8 °C | 31.2 °C | 107.44 mm |
| September | 15.2 °C | 28.5 °C | 108.97 mm |
| October | 8.4 °C | 22.7 °C | 106.43 mm |
| November | 2.7 °C | 16.2 °C | 105.66 mm |
| December | -0.3 °C | 11 °C | 160.02 mm |
| Annual | 8.8 °C | 21.4 °C | 1530.61 mm |
| Average First Frost Date | Oct. 21 - Oct. 31 |
| Average Last Frost Date | Apr. 1 - Apr. 10 |
| Average Days With Frost | 75-100 Days |
| Plant Hardiness Zone | Zone 7b : -15°C to -12.2°C |
| Plant Hardiness Zone - 2012 | Zone 7a : -17.8°C to -15°C |
| Current Drought Conditions | Abnormally Dry |
| Köppen Climate Classification | Cfa - Humid Subtropical Climate |