Keystone, SD
Climate overview — based on NOAA 1991-2020 normals from MT RUSHMORE NMEM, SD US.
Year-round temperatures (°F)
Climate summary
Keystone has an annual average temperature of 45.7°F with about 24.1 inches of precipitation per year and 59.3 inches of snow. The warmest month is July (average high 78.7°F), and the coldest is February (average low 18.4°F). May is typically the wettest month (4.80 in) and January the driest (0.48 in). Snow typically falls from January through December.
Best time to visit Keystone
Full guide →Climate change signal
All-time records →52 of 366 (14.2%) of Keystone's all-time daily heat records have been set since 2015. If records were spread evenly across the station's history, only about 5% would fall in any given decade.
| 1960s | 50 | |
| 1970s | 68 | |
| 1980s | 82 | |
| 1990s | 50 | |
| 2000s | 47 | |
| 2010s | 35 | |
| 2020s | 34 |
Bars: number of all-time daily heat records still standing that were set in each decade.
Monthly averages
| Month | Avg High | Avg Low | Avg Temp | Precipitation | Snow | Rainy days |
|---|---|---|---|---|---|---|
| January | 36.8°F | 18.8°F | 27.8°F | 0.48 in | 7.2 in | 5 |
| February | 36.3°F | 18.4°F | 27.3°F | 0.76 in | 8.9 in | 6 |
| March | 44.2°F | 25.4°F | 34.8°F | 1.35 in | 9.6 in | 7 |
| April | 50.2°F | 31.8°F | 41.0°F | 2.62 in | 13.1 in | 10 |
| May | 59.6°F | 41.5°F | 50.6°F | 4.80 in | 1.5 in | 14 |
| June | 71.1°F | 51.9°F | 61.5°F | 3.58 in | 0.2 in | 13 |
| July | 78.7°F | 59.1°F | 68.9°F | 3.59 in | — | 12 |
| August | 77.5°F | 58.0°F | 67.8°F | 2.29 in | — | 11 |
| September | 69.1°F | 49.6°F | 59.4°F | 1.76 in | 0.9 in | 8 |
| October | 55.0°F | 36.8°F | 45.9°F | 1.80 in | 4.9 in | 7 |
| November | 44.4°F | 27.0°F | 35.7°F | 0.59 in | 6.4 in | 5 |
| December | 36.6°F | 19.8°F | 28.2°F | 0.50 in | 6.6 in | 5 |
Climate twins of Keystone
Why these? →The most climatically similar US cities at least 140 miles away (by monthly temperature + precipitation pattern).