Bancroft, Idaho has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from -1.6 °C (low) to 14 °C (high). Annual precipitation averages 390.9 Millimeters. Bancroft is located in USDA Plant Hardiness Zone 5a. The growing season typically runs from the last frost around May 11 - May 20 through the first frost around Sep. 21 - Sep. 30.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -11.4 °C | -0.4 °C | 34.54 mm |
| February | -10 °C | 1.9 °C | 28.96 mm |
| March | -5.7 °C | 7.2 °C | 36.83 mm |
| April | -1.9 °C | 12.6 °C | 36.83 mm |
| May | 2.3 °C | 18.2 °C | 54.86 mm |
| June | 5.6 °C | 23.6 °C | 33.27 mm |
| July | 8.8 °C | 29.8 °C | 19.81 mm |
| August | 8.1 °C | 29.3 °C | 26.16 mm |
| September | 3.5 °C | 23.4 °C | 33.53 mm |
| October | -1.4 °C | 15.2 °C | 35.05 mm |
| November | -6.4 °C | 6.4 °C | 24.38 mm |
| December | -10.7 °C | 0.2 °C | 26.67 mm |
| Annual | -1.6 °C | 14 °C | 390.89 mm |
| Average First Frost Date | Sep. 21 - Sep. 30 |
| Average Last Frost Date | May 11 - May 20 |
| Average Days With Frost | 150-180 Days |
| Plant Hardiness Zone | Zone 5a : -28.9°C to -26.1°C |
| Plant Hardiness Zone - 2012 | Zone 5a : -28.9°C to -26.1°C |
| Current Drought Conditions | Extreme Drought |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |