Brewster, Minnesota has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 35.3 °F (low) to 54.7 °F (high). Annual precipitation averages 30.2 Inches. Brewster is located in USDA Plant Hardiness Zone 5a. The growing season typically runs from the last frost around Apr. 21 - Apr. 30 through the first frost around Oct. 1 - Oct. 10.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 6.3 °F | 23.2 °F | 0.73 in. |
| February | 10.2 °F | 27.5 °F | 0.85 in. |
| March | 21.9 °F | 40.0 °F | 1.55 in. |
| April | 34.1 °F | 55.3 °F | 3.01 in. |
| May | 46.9 °F | 67.9 °F | 4.26 in. |
| June | 58.1 °F | 78.2 °F | 4.58 in. |
| July | 61.9 °F | 82.0 °F | 3.63 in. |
| August | 59.1 °F | 79.3 °F | 3.67 in. |
| September | 50.6 °F | 73.0 °F | 3.23 in. |
| October | 37.3 °F | 58.9 °F | 2.33 in. |
| November | 24.2 °F | 42.2 °F | 1.36 in. |
| December | 12.4 °F | 28.3 °F | 1.0 in. |
| Annual | 35.3 °F | 54.7 °F | 30.2 in. |
| Average First Frost Date | Oct. 1 - Oct. 10 |
| Average Last Frost Date | Apr. 21 - Apr. 30 |
| Average Days With Frost | 150-180 Days |
| Plant Hardiness Zone | Zone 5a : -20°F to -15°F |
| Plant Hardiness Zone - 2012 | Zone 4b : -25°F to -20°F |
| Current Drought Conditions | Abnormally Dry |
| Köppen Climate Classification | Dfa - Humid Continental Hot Summers With Year Around Precipitation |