Anaconda, Montana has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from -2.7 °C (low) to 12.7 °C (high). Annual precipitation averages 369.3 Millimeters. Anaconda is located in USDA Plant Hardiness Zone 4b. The growing season typically runs from the last frost around May 11 - May 20 through the first frost around Aug. 11 - Aug. 20.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -10.8 °C | 1.1 °C | 14.99 mm |
| February | -10.3 °C | 2.4 °C | 18.03 mm |
| March | -6.8 °C | 6.8 °C | 26.16 mm |
| April | -3.3 °C | 11.1 °C | 33.02 mm |
| May | 0.7 °C | 16.6 °C | 55.37 mm |
| June | 4.3 °C | 21 °C | 60.2 mm |
| July | 7.1 °C | 27.2 °C | 33.53 mm |
| August | 6.1 °C | 26.9 °C | 33.78 mm |
| September | 2.3 °C | 21.2 °C | 26.92 mm |
| October | -2.4 °C | 13.1 °C | 25.15 mm |
| November | -7.5 °C | 5.2 °C | 23.11 mm |
| December | -11.4 °C | 0.3 °C | 19.05 mm |
| Annual | -2.7 °C | 12.7 °C | 369.31 mm |
| Average First Frost Date | Aug. 11 - Aug. 20 |
| Average Last Frost Date | May 11 - May 20 |
| Average Days With Frost | Over 180 Days |
| Plant Hardiness Zone | Zone 4b : -31.7°C to -28.9°C |
| Plant Hardiness Zone - 2012 | Zone 4b : -31.7°C to -28.9°C |
| Current Drought Conditions | Moderate Drought |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |