Brookston, Minnesota has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 29.3 °F (low) to 50.4 °F (high). Annual precipitation averages 30.5 Inches. Brookston is located in USDA Plant Hardiness Zone 4a. The growing season typically runs from the last frost around May 21 - May 31 through the first frost around Sep. 21 - Sep. 30.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -0.3 °F | 19.1 °F | 0.88 in. |
| February | 2.9 °F | 24.7 °F | 0.82 in. |
| March | 15.2 °F | 37.2 °F | 1.28 in. |
| April | 27.9 °F | 50.0 °F | 2.39 in. |
| May | 39.5 °F | 63.9 °F | 3.39 in. |
| June | 49.2 °F | 73.3 °F | 4.58 in. |
| July | 54.7 °F | 78.2 °F | 4.17 in. |
| August | 53.3 °F | 76.5 °F | 3.72 in. |
| September | 45.8 °F | 67.9 °F | 3.33 in. |
| October | 34.2 °F | 53.1 °F | 3.03 in. |
| November | 21.5 °F | 37.0 °F | 1.56 in. |
| December | 7.9 °F | 24.1 °F | 1.32 in. |
| Annual | 29.3 °F | 50.4 °F | 30.47 in. |
| Average First Frost Date | Sep. 21 - Sep. 30 |
| Average Last Frost Date | May 21 - May 31 |
| Average Days With Frost | Over 180 Days |
| Plant Hardiness Zone | Zone 4a : -30°F to -25°F |
| Plant Hardiness Zone - 2012 | Zone 3b : -35°F to -30°F |
| Current Drought Conditions | Abnormally Dry |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |