Siloam Springs, Arkansas has a Humid Subtropical Climate climate (Köppen classification: Cfa). Average annual temperatures range from 8.7 °C (low) to 20.7 °C (high). Annual precipitation averages 1258.3 Millimeters. Siloam Springs is located in USDA Plant Hardiness Zone 7a. The growing season typically runs from the last frost around Apr. 1 - Apr. 10 through the first frost around Oct. 21 - Oct. 31.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -3.2 °C | 8.3 °C | 70.61 mm |
| February | -1.4 °C | 10.8 °C | 61.72 mm |
| March | 3.3 °C | 15.7 °C | 102.87 mm |
| April | 7.9 °C | 20.6 °C | 125.48 mm |
| May | 13.2 °C | 24.8 °C | 153.92 mm |
| June | 18.2 °C | 29.3 °C | 122.17 mm |
| July | 20.4 °C | 32.2 °C | 115.32 mm |
| August | 19.6 °C | 32.1 °C | 88.65 mm |
| September | 15.2 °C | 27.9 °C | 124.46 mm |
| October | 8.8 °C | 21.9 °C | 117.86 mm |
| November | 3.2 °C | 15.4 °C | 93.98 mm |
| December | -1.4 °C | 9.8 °C | 81.28 mm |
| Annual | 8.7 °C | 20.7 °C | 1258.32 mm |
| Average First Frost Date | Oct. 21 - Oct. 31 |
| Average Last Frost Date | Apr. 1 - Apr. 10 |
| Average Days With Frost | 75-100 Days |
| Plant Hardiness Zone | Zone 7a : -17.8°C to -15°C |
| Plant Hardiness Zone - 2012 | Zone 7a : -17.8°C to -15°C |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Cfa - Humid Subtropical Climate |