Princeton, Idaho has a Humid Continental Climate - Dry Cool Summer climate (Köppen classification: Dsb). Average annual temperatures range from 2.4 °C (low) to 14.7 °C (high). Annual precipitation averages 605.5 Millimeters. Princeton is located in USDA Plant Hardiness Zone 6b. The growing season typically runs from the last frost around May 11 - May 20 through the first frost around Sep.11 - Sep. 20.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -3.4 °C | 2.9 °C | 73.41 mm |
| February | -3 °C | 5.1 °C | 55.88 mm |
| March | -1 °C | 9.2 °C | 61.21 mm |
| April | 1.6 °C | 13.5 °C | 54.86 mm |
| May | 4.9 °C | 18.8 °C | 59.69 mm |
| June | 7.6 °C | 21.8 °C | 43.18 mm |
| July | 9.6 °C | 28.2 °C | 17.78 mm |
| August | 9.3 °C | 29 °C | 16.26 mm |
| September | 5.9 °C | 23.6 °C | 21.59 mm |
| October | 2.1 °C | 15.3 °C | 52.32 mm |
| November | -0.9 °C | 7.1 °C | 72.9 mm |
| December | -3.9 °C | 2.3 °C | 76.45 mm |
| Annual | 2.4 °C | 14.7 °C | 605.53 mm |
| Average First Frost Date | Sep.11 - Sep. 20 |
| Average Last Frost Date | May 11 - May 20 |
| Average Days With Frost | 125-150 Days |
| Plant Hardiness Zone | Zone 6b : -20.6°C to -17.8°C |
| Plant Hardiness Zone - 2012 | Zone 6a : -23.3°C to -20.6°C |
| Current Drought Conditions | Severe Drought |
| Köppen Climate Classification | Dsb - Humid Continental Climate - Dry Cool Summer |