Oldham, South Dakota has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 34.2 °F (low) to 54.9 °F (high). Annual precipitation averages 25.8 Inches. Oldham is located in USDA Plant Hardiness Zone 4b. The growing season typically runs from the last frost around May 1 - May 10 through the first frost around Oct. 1 - Oct. 10.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 5.4 °F | 23.6 °F | 0.57 in. |
| February | 9.7 °F | 28.6 °F | 0.71 in. |
| March | 21.0 °F | 40.6 °F | 1.18 in. |
| April | 33.2 °F | 55.6 °F | 2.6 in. |
| May | 45.8 °F | 68.0 °F | 3.65 in. |
| June | 56.6 °F | 77.7 °F | 4.1 in. |
| July | 60.9 °F | 82.4 °F | 3.3 in. |
| August | 58.5 °F | 80.0 °F | 3.09 in. |
| September | 49.6 °F | 73.0 °F | 2.82 in. |
| October | 36.2 °F | 58.8 °F | 2.13 in. |
| November | 22.7 °F | 42.1 °F | 0.94 in. |
| December | 11.2 °F | 28.5 °F | 0.72 in. |
| Annual | 34.2 °F | 54.9 °F | 25.81 in. |
| Average First Frost Date | Oct. 1 - Oct. 10 |
| Average Last Frost Date | May 1 - May 10 |
| Average Days With Frost | 150-180 Days |
| Plant Hardiness Zone | Zone 4b : -25°F to -20°F |
| Plant Hardiness Zone - 2012 | Zone 4b : -25°F to -20°F |
| Current Drought Conditions | Severe Drought |
| Köppen Climate Classification | Dfa - Humid Continental Hot Summers With Year Around Precipitation |