Grand Rivers, Kentucky has a Humid Subtropical Climate climate (Köppen classification: Cfa). Average annual temperatures range from 9 °C (low) to 20.8 °C (high). Annual precipitation averages 1329.2 Millimeters. Grand Rivers is located in USDA Plant Hardiness Zone 7a. 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 | -2.7 °C | 7.3 °C | 105.41 mm |
| February | -1.1 °C | 9.8 °C | 100.84 mm |
| March | 3.3 °C | 15.3 °C | 120.9 mm |
| April | 8.5 °C | 21.5 °C | 130.05 mm |
| May | 13.9 °C | 25.9 °C | 144.78 mm |
| June | 18.8 °C | 30.3 °C | 115.32 mm |
| July | 20.8 °C | 32.3 °C | 108.46 mm |
| August | 19.7 °C | 31.8 °C | 84.84 mm |
| September | 15.4 °C | 28.6 °C | 87.12 mm |
| October | 9.2 °C | 22.2 °C | 98.3 mm |
| November | 3.2 °C | 14.9 °C | 108.71 mm |
| December | -0.9 °C | 9.1 °C | 124.46 mm |
| Annual | 9 °C | 20.8 °C | 1329.19 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 7a : -17.8°C to -15°C |
| Plant Hardiness Zone - 2012 | Zone 7a : -17.8°C to -15°C |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Cfa - Humid Subtropical Climate |