Putnam, Texas has a Humid Subtropical Climate climate (Köppen classification: Cfa). Average annual temperatures range from 11.1 °C (low) to 24.9 °C (high). Annual precipitation averages 727.5 Millimeters. Putnam is located in USDA Plant Hardiness Zone 8a. The growing season typically runs from the last frost around Mar. 21 - Mar. 31 through the first frost around Nov. 11 - Nov. 20.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -0.1 °C | 14.2 °C | 30.99 mm |
| February | 2.1 °C | 16.3 °C | 44.2 mm |
| March | 6.2 °C | 20.6 °C | 57.66 mm |
| April | 10.3 °C | 25.1 °C | 52.58 mm |
| May | 15.8 °C | 29 °C | 100.84 mm |
| June | 20.1 °C | 32.8 °C | 98.04 mm |
| July | 21.8 °C | 35.1 °C | 50.29 mm |
| August | 21.4 °C | 35.1 °C | 57.4 mm |
| September | 17.4 °C | 31.1 °C | 75.18 mm |
| October | 11.4 °C | 25.9 °C | 71.63 mm |
| November | 5.4 °C | 19.4 °C | 52.32 mm |
| December | 0.8 °C | 14.6 °C | 36.32 mm |
| Annual | 11.1 °C | 24.9 °C | 727.45 mm |
| Average First Frost Date | Nov. 11 - Nov. 20 |
| Average Last Frost Date | Mar. 21 - Mar. 31 |
| Average Days With Frost | 50-75 Days |
| Plant Hardiness Zone | Zone 8a : -12.2°C to -9.4°C |
| Plant Hardiness Zone - 2012 | Zone 8a : -12.2°C to -9.4°C |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Cfa - Humid Subtropical Climate |