Last Frost Date Rapid City: Frost Dates, Late Frost Risk & Growing Season
When is the last spring frost and the first autumn frost in Rapid City? Frost dates from 30 years of data, the risk of late frost, frost-free days and planting dates.
The frost season in Rapid City
- Last frost (average): May 12
- In 1 year out of 10 it still freezes on May 21.
- First frost: October 2
- Frost-free season: 141 days
- Frost after 15 May: in 23 % of years
Frost days per month in Rapid City
- January: 30.9 · -11 °C
- February: 27.6 · -10 °C
- March: 27 · -5 °C
- April: 16.2 · -1 °C
- May: 3.5 · 5 °C
- June: 0 · 11 °C
- July: 0 · 15 °C
- August: 0 · 14 °C
- September: 1 · 8 °C
- October: 13.2 · 1 °C
- November: 26.2 · -5 °C
- December: 30.7 · -10 °C
- Matched to the average lows of a weather station 13 km away – accurate to about ±1–2 weeks.
- Daily minimum temperatures 2 m above ground over 30 years (1991–2020), NASA POWER; station data: Deutscher Wetterdienst (CC BY 4.0). Ground frost can form while the air at 2 m is still +2 to +3 °C.