Bancroft, Idaho has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 29.1 °F (low) to 57.1 °F (high). Annual precipitation averages 15.4 Inches. 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 | 11.5 °F | 31.2 °F | 1.36 in. |
| February | 14.0 °F | 35.4 °F | 1.14 in. |
| March | 21.8 °F | 45.0 °F | 1.45 in. |
| April | 28.6 °F | 54.6 °F | 1.45 in. |
| May | 36.1 °F | 64.7 °F | 2.16 in. |
| June | 42.0 °F | 74.5 °F | 1.31 in. |
| July | 47.8 °F | 85.6 °F | 0.78 in. |
| August | 46.5 °F | 84.7 °F | 1.03 in. |
| September | 38.3 °F | 74.1 °F | 1.32 in. |
| October | 29.4 °F | 59.4 °F | 1.38 in. |
| November | 20.4 °F | 43.6 °F | 0.96 in. |
| December | 12.7 °F | 32.4 °F | 1.05 in. |
| Annual | 29.1 °F | 57.1 °F | 15.39 in. |
| 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 : -20°F to -15°F |
| Plant Hardiness Zone - 2012 | Zone 5a : -20°F to -15°F |
| Current Drought Conditions | Extreme Drought |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |