Caribou, Maine has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 30.1 °F (low) to 50 °F (high). Annual precipitation averages 41.8 Inches. Caribou is located in USDA Plant Hardiness Zone 4a. 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 | 0.5 °F | 20.9 °F | 3.4 in. |
| February | 1.6 °F | 23.9 °F | 2.55 in. |
| March | 13.6 °F | 33.6 °F | 2.88 in. |
| April | 28.4 °F | 47.3 °F | 3.18 in. |
| May | 40.5 °F | 62.2 °F | 3.34 in. |
| June | 49.9 °F | 71.5 °F | 3.88 in. |
| July | 55.9 °F | 76.6 °F | 4.08 in. |
| August | 53.7 °F | 75.5 °F | 3.73 in. |
| September | 45.9 °F | 67.3 °F | 3.5 in. |
| October | 35.0 °F | 53.7 °F | 4.12 in. |
| November | 25.1 °F | 39.7 °F | 3.43 in. |
| December | 11.4 °F | 27.9 °F | 3.72 in. |
| Annual | 30.1 °F | 50 °F | 41.81 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 4a : -30°F to -25°F |
| Plant Hardiness Zone - 2012 | Zone 4a : -30°F to -25°F |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |