Monterey, Indiana has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 4.5 °C (low) to 15.5 °C (high). Annual precipitation averages 1053.1 Millimeters. Monterey is located in USDA Plant Hardiness Zone 5b. The growing season typically runs from the last frost around Apr. 21 - Apr. 30 through the first frost around Oct. 11 - Oct. 20.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -8.8 °C | -0.1 °C | 66.8 mm |
| February | -7.3 °C | 2.3 °C | 60.2 mm |
| March | -2.4 °C | 8.6 °C | 66.8 mm |
| April | 3.4 °C | 15.5 °C | 95.76 mm |
| May | 9.8 °C | 21.7 °C | 112.27 mm |
| June | 15.2 °C | 26.9 °C | 116.59 mm |
| July | 16.8 °C | 28.7 °C | 119.13 mm |
| August | 15.8 °C | 27.6 °C | 110.24 mm |
| September | 11.5 °C | 24.6 °C | 87.12 mm |
| October | 5.2 °C | 17.7 °C | 81.28 mm |
| November | -0.3 °C | 9.4 °C | 76.2 mm |
| December | -5.4 °C | 2.9 °C | 60.71 mm |
| Annual | 4.5 °C | 15.5 °C | 1053.1 mm |
| Average First Frost Date | Oct. 11 - Oct. 20 |
| Average Last Frost Date | Apr. 21 - Apr. 30 |
| Average Days With Frost | 125-150 Days |
| Plant Hardiness Zone | Zone 5b : -26.1°C to -23.3°C |
| Plant Hardiness Zone - 2012 | Zone 5b : -26.1°C to -23.3°C |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Dfa - Humid Continental Hot Summers With Year Around Precipitation |