Petersburg, Kentucky has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 44.4 °F (low) to 65 °F (high). Annual precipitation averages 45.2 Inches. Petersburg is located in USDA Plant Hardiness Zone 6b. 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 | 23.4 °F | 39.8 °F | 3.35 in. |
| February | 25.3 °F | 43.8 °F | 2.85 in. |
| March | 32.9 °F | 53.5 °F | 4.0 in. |
| April | 42.8 °F | 66.0 °F | 4.68 in. |
| May | 53.2 °F | 74.9 °F | 4.85 in. |
| June | 61.6 °F | 83.3 °F | 4.53 in. |
| July | 65.8 °F | 86.6 °F | 3.95 in. |
| August | 64.7 °F | 86.1 °F | 3.28 in. |
| September | 56.7 °F | 80.0 °F | 3.31 in. |
| October | 44.0 °F | 67.7 °F | 3.32 in. |
| November | 34.4 °F | 54.7 °F | 3.44 in. |
| December | 28.1 °F | 44.1 °F | 3.63 in. |
| Annual | 44.4 °F | 65 °F | 45.19 in. |
| Average First Frost Date | Oct. 21 - Oct. 31 |
| Average Last Frost Date | Apr. 11 - Apr. 20 |
| Average Days With Frost | 75-100 Days |
| Plant Hardiness Zone | Zone 6b : -5°F to 0°F |
| Plant Hardiness Zone - 2012 | Zone 6a : -10°F to -5°F |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Dfa - Humid Continental Hot Summers With Year Around Precipitation |