Fillmore, Indiana has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 5.7 °C (low) to 16.3 °C (high). Annual precipitation averages 1158.5 Millimeters. Fillmore is located in USDA Plant Hardiness Zone 6a. The growing season typically runs from the last frost around Apr. 21 - Apr. 30 through the first frost around Oct. 11 - Oct. 20.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -7 °C | 1.7 °C | 81.03 mm |
| February | -5.5 °C | 4.2 °C | 67.06 mm |
| March | -0.5 °C | 10.2 °C | 85.09 mm |
| April | 5.1 °C | 16.6 °C | 118.11 mm |
| May | 11.1 °C | 22.2 °C | 125.98 mm |
| June | 16.1 °C | 26.9 °C | 134.37 mm |
| July | 17.7 °C | 28.4 °C | 117.86 mm |
| August | 16.5 °C | 27.8 °C | 79.5 mm |
| September | 12.6 °C | 24.9 °C | 91.95 mm |
| October | 6.1 °C | 18.1 °C | 88.9 mm |
| November | 0.4 °C | 10.5 °C | 92.2 mm |
| December | -4.3 °C | 4.1 °C | 76.45 mm |
| Annual | 5.7 °C | 16.3 °C | 1158.5 mm |
| Average First Frost Date | Oct. 11 - Oct. 20 |
| Average Last Frost Date | Apr. 21 - Apr. 30 |
| Average Days With Frost | 125-150 Days |
| Plant Hardiness Zone | Zone 6a : -23.3°C to -20.6°C |
| Plant Hardiness Zone - 2012 | Zone 5b : -26.1°C to -23.3°C |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Dfa - Humid Continental Hot Summers With Year Around Precipitation |