Big Flats, New York has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 2.7 °C (low) to 14.9 °C (high). Annual precipitation averages 905.5 Millimeters. Big Flats is located in USDA Plant Hardiness Zone 6a. The growing season typically runs from the last frost around May 11 - May 20 through the first frost around Oct. 1 - Oct. 10.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -9.2 °C | 0.8 °C | 53.85 mm |
| February | -8.7 °C | 2.2 °C | 45.72 mm |
| March | -4.7 °C | 6.9 °C | 66.29 mm |
| April | 0.9 °C | 14.4 °C | 75.69 mm |
| May | 6.9 °C | 21.2 °C | 75.95 mm |
| June | 12 °C | 25.6 °C | 96.27 mm |
| July | 14.4 °C | 28.2 °C | 92.46 mm |
| August | 13.7 °C | 27.3 °C | 95.76 mm |
| September | 9.8 °C | 23.4 °C | 88.65 mm |
| October | 3.7 °C | 16.2 °C | 88.14 mm |
| November | -1.3 °C | 9.4 °C | 66.29 mm |
| December | -5.4 °C | 3.4 °C | 60.45 mm |
| Annual | 2.7 °C | 14.9 °C | 905.52 mm |
| Average First Frost Date | Oct. 1 - Oct. 10 |
| Average Last Frost Date | May 11 - May 20 |
| 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 | Dfb - Humid Continental Mild Summer, Wet All Year |