| 2023 Hardiness Zone: | Zone 6a: -10°F to -5°F Zone 6b: -5°F to 0°F Zone 4b: -25°F to -20°F Zone 4a: -30°F to -25°F Zone 5a: -20°F to -15°F Zone 5b: -15°F to -10°F | |
| 2012 Hardiness Zone: | Zone 6a: -10°F to -5°F Zone 6b: -5°F to 0°F Zone 4b: -25°F to -20°F Zone 4a: -30°F to -25°F Zone 5a: -20°F to -15°F Zone 5b: -15°F to -10°F | |
| 1990 Hardiness Zone: | Zone 1b: -15F to -10F | |
| Average First Frost Date: | Sep. 21 - Sep. 30 | |
| Average Last Frost Date: | May 21 - May 31 | |
| Koppen-Geiger Climate Zone: | Dfb - Humid Continental Mild Summer, Wet All Year | |
| Ecoregion: | 15l - Salish Mountains | |
| Current Drought Status: | Exceptional Drought | |
| Heat Zone Days: | 31 - 45 days Over 86°F |
Annual Climate Data for ZIP Code 59923 - Libby, MT | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Annual |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg Min Temp (°F) | 18 | 22 | 27 | 31 | 38 | 45 | 48 | 47 | 39 | 32 | 27 | 20 | 33 |
| Avg Max Temp (°F) | 33 | 41 | 51 | 61 | 71 | 78 | 85 | 86 | 74 | 58 | 41 | 33 | 59 |
| Avg Precip (In.) | 1.95 | 1.4 | 1.27 | 1.03 | 1.57 | 1.62 | 1.3 | .98 | .99 | 1.37 | 2.42 | 2.19 | 18.1 |