Alamo, Indiana has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 5 °C (low) to 16.2 °C (high). Annual precipitation averages 1097.3 Millimeters. Alamo 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 | -7.9 °C | 1.3 °C | 71.37 mm |
| February | -6.6 °C | 3.5 °C | 61.21 mm |
| March | -1.4 °C | 9.7 °C | 78.74 mm |
| April | 4.4 °C | 16.5 °C | 113.54 mm |
| May | 10.6 °C | 22.4 °C | 118.11 mm |
| June | 15.6 °C | 27.1 °C | 128.27 mm |
| July | 17.1 °C | 28.6 °C | 111.76 mm |
| August | 15.8 °C | 27.9 °C | 89.41 mm |
| September | 11.6 °C | 25.2 °C | 80.77 mm |
| October | 5.4 °C | 18.4 °C | 84.33 mm |
| November | -0.2 °C | 10.3 °C | 88.14 mm |
| December | -4.9 °C | 3.7 °C | 71.63 mm |
| Annual | 5 °C | 16.2 °C | 1097.28 mm |
| Average First Frost Date | Oct. 11 - Oct. 20 |
| Average Last Frost Date | Apr. 21 - Apr. 30 |
| Average Days With Frost | 100-125 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 |