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The temperatures in Rapid City in May are quite cold with temperatures between 7°C and 18°C, warm clothes are a must.
You can expect rain for roughly half of the month of May in Rapid City. We’re expecting roughly 8 to 15 days of rain, so your rubber boots and umbrella are going to see plenty of use this month if you’re keen on staying dry.
Please note that Rapid City can expect a few days of snow in May.
Our weather forecast can give you a great sense of what weather to expect in Rapid City in May 2025.
If you’re planning to visit Rapid City in the near future, we highly recommend that you review the 14 day weather forecast for Rapid City before you arrive.
| Month | Temperatures | Rainy Days | Dry Days | Snowy Days | Rainfall | Weather | More details |
|---|---|---|---|---|---|---|---|
| January | 1° / -7° | 5 | 14 | 13 | 23 mm | Awful | Rapid City in January |
| February | 1° / -8° | 5 | 10 | 14 | 35 mm | Awful | Rapid City in February |
| March | 8° / -2° | 5 | 17 | 10 | 57 mm | Bad | Rapid City in March |
| April | 12° / 1° | 7 | 16 | 7 | 115 mm | Awful | Rapid City in April |
| May | 18° / 7° | 10 | 19 | 2 | 139 mm | Bad | Rapid City in May |
| June | 26° / 13° | 7 | 23 | 0 | 122 mm | Good | Rapid City in June |
| July | 30° / 18° | 7 | 24 | 0 | 117 mm | Ok | Rapid City in July |
| August | 29° / 17° | 6 | 25 | 0 | 96 mm | Good | Rapid City in August |
| September | 24° / 13° | 3 | 27 | 0 | 56 mm | Perfect | Rapid City in September |
| October | 14° / 4° | 3 | 23 | 4 | 63 mm | Ok | Rapid City in October |
| November | 8° / -1° | 3 | 21 | 6 | 25 mm | Bad | Rapid City in November |
| December | 1° / -7° | 3 | 17 | 11 | 30 mm | Awful | Rapid City in December |