Climate averages 1991–2020
Rapid City weather
in April.
A cool, moderately wet month: the 7th warmest and the 10th driest of the year.
Long-term climate patterns, not a forecast for a particular trip.
April is a cool month in Rapid City: daytime highs average 12.8°C and nights cool to about 1.1°C. By daytime temperature it is the 7th warmest of the 12 months.
Expect about 80 mm of rain on roughly 12 days, which makes April a moderately wet month (the 10th driest of the 12 months). Daylight, from sunrise to sunset, lasts about 13 h 25 min on an average April day.
The nearest other city in this atlas is Bismarck (358 km away). In April its highs average 11.4°C, 1.4°C cooler than Rapid City, with 46 mm of rain.
Among the 498 cities listed in the United States, Rapid City ranks joint 462nd of 498 for the warmest April highs and joint 222nd of 498 for the driest April (rainfall, lowest first). The mean April high of those 498 cities is 19.4°C; Rapid City is 6.6°C cooler than that mean.
From April to May, average highs rise by 5.7°C to 18.4°C, and monthly rainfall rises from 80 mm to 112 mm.
The annual picture
April in context
Monthly rainfall
Average total · mmAverages from hourly ERA5 reanalysis data. Actual weather varies from year to year. How these numbers are calculated
Every month, side by side
Rapid City climate table
| Month | Average highHigh / low | Average low | Rainfall mm/month | Rain days ≥1 mm/day | Daylight hours/dayDaylight h/day |
|---|---|---|---|---|---|
| January | 2.5°C-8.1°C | -8.1°C | 13 | 3.9 | 9.39 h |
| February | 3.5°C-7.6°C | -7.6°C | 20 | 5.1 | 10.410 h |
| March | 8.5°C-3.5°C | -3.5°C | 40 | 7.6 | 11.912 h |
| April, selected | 12.8°C1.1°C | 1.1°C | 80 | 11.8 | 13.413 h |
| May | 18.4°C7.2°C | 7.2°C | 112 | 14.1 | 14.715 h |
| June | 24.4°C12.9°C | 12.9°C | 97 | 14.5 | 15.415 h |
| July | 28.9°C16.9°C | 16.9°C | 78 | 13.4 | 15.115 h |
| August | 28.2°C16.1°C | 16.1°C | 60 | 10.8 | 14.014 h |
| September | 23.3°C11.2°C | 11.2°C | 42 | 6.7 | 12.613 h |
| October | 14.9°C3.9°C | 3.9°C | 50 | 7.3 | 11.011 h |
| November | 7.9°C-2.5°C | -2.5°C | 20 | 4.4 | 9.710 h |
| December | 2.8°C-6.9°C | -6.9°C | 15 | 3.6 | 9.09 h |
Rainfall is the average of the 30 separate monthly totals. A rain day is a local calendar day with at least 1 mm of precipitation. Daylight is the calculated sunrise-to-sunset length, not measured sunshine.
Compare places
April in nearby cities
- Bismarck in AprilUnited States · 358 kmHigh 11.4°C · Low -0.1°C · 46 mm rain
- Fort Collins in AprilUnited States · 417 kmHigh 14.5°C · Low 0.3°C · 64 mm rain
- Greeley in AprilUnited States · 424 kmHigh 16.9°C · Low 2.2°C · 49 mm rain
- Loveland in AprilUnited States · 437 kmHigh 14.7°C · Low 0.2°C · 64 mm rain
- Billings in AprilUnited States · 456 kmHigh 13.9°C · Low 1.2°C · 59 mm rain
- Longmont in AprilUnited States · 462 kmHigh 14.8°C · Low 0.4°C · 67 mm rain
- Boulder in AprilUnited States · 482 kmHigh 13.7°C · Low -0.4°C · 78 mm rain
- Thornton in AprilUnited States · 490 kmHigh 14.4°C · Low -0.4°C · 70 mm rain
Read the numbers correctly
Climate, not a promise.
These patterns help compare months. They cannot tell you the weather on a specific day of your trip.
Sources, method and limitsHow these numbers are made (what the highs, lows and rain days mean, the sources and the model cell used for Rapid City) is explained once on the Rapid City year overview and on the Sources, method and limits page.