Rapid City weather in May: Rapid City, South Dakota: normal highs, lows, rain and records for May
Rapid City in May has a normal high of 67°F and a normal low of 42°F, a daily mean of 54°F, rising from 61°F on the 1st to 72°F by the 31st. Measurable precipitation falls on 13 days in a normal May, 3.45 inches in all. (NOAA 1991-2020 normals)
In metric: a normal high of 19°C and low of 5°C, 88 mm of precipitation and 4 cm of snow in May.
- NOAA stationRapid City Regional Airport
- Station IDUSW00024090
- Location44.04°N 103.05°W
- Elevation3,160 ft (963 m)
- Population79,894
- Jan 36° 13°
- Feb 38° 14°
- Mar 48° 23°
- Apr 57° 31°
- May 67° 42°
- Jun 78° 52°
- Jul 86° 59°
- Aug 85° 56°
- Sep 76° 46°
- Oct 60° 34°
- Nov 47° 22°
- Dec 37° 14°
Each month: normal high (large) and low, °F. Fill: the month's normal mean, colder blue to hotter red.
How warm is Rapid City in May?
The normal high is 67°F and the normal low 42°F, for a daily mean of 54.1°F. May is 10.2°F warmer than April and 10.5°F cooler than June. May is the 5th warmest month of the year in Rapid City and the wettest. Across the month the normal high rises 11°F, from 61°F on May 1 to 72°F on May 31. From one year to the next May's mean temperature typically moves about 2.8°F either way (NOAA's standard deviation), so roughly two Mays in three average between 51°F and 57°F.
Bars above: each day's normal high to low. Columns below: the chance of 0.01 inch or more of precipitation that day, on a scale of 0 to 100% (highest 44%).
| Day | High | Low | Chance of 0.01 in | Chance of 0.10 in |
|---|---|---|---|---|
| May 1 | 61°F | 36°F | 37% | 19% |
| May 8 | 63°F | 39°F | 39% | 21% |
| May 15 | 66°F | 41°F | 41% | 22% |
| May 22 | 69°F | 44°F | 43% | 23% |
| May 31 | 72°F | 47°F | 44% | 24% |
Every day of May: normal high, low and chance of precipitation (warmest afternoon May 31, coldest night May 1)
| Day | High | Low | Chance of 0.01 in | Chance of 0.10 in | Daylight |
|---|---|---|---|---|---|
| May 1 | 61°F | 36°F | 37% | 19% | 14 h 10 min |
| May 2 | 61°F | 36°F | 38% | 19% | 14 h 10 min |
| May 3 | 62°F | 37°F | 38% | 20% | 14 h 10 min |
| May 4 | 62°F | 37°F | 38% | 20% | 14 h 20 min |
| May 5 | 62°F | 37°F | 38% | 20% | 14 h 20 min |
| May 6 | 63°F | 38°F | 39% | 20% | 14 h 20 min |
| May 7 | 63°F | 38°F | 39% | 20% | 14 h 20 min |
| May 8 | 63°F | 39°F | 39% | 21% | 14 h 30 min |
| May 9 | 64°F | 39°F | 39% | 21% | 14 h 30 min |
| May 10 | 64°F | 39°F | 40% | 21% | 14 h 30 min |
| May 11 | 65°F | 40°F | 40% | 21% | 14 h 30 min |
| May 12 | 65°F | 40°F | 40% | 21% | 14 h 40 min |
| May 13 | 65°F | 41°F | 40% | 21% | 14 h 40 min |
| May 14 | 66°F | 41°F | 41% | 21% | 14 h 40 min |
| May 15 | 66°F | 41°F | 41% | 22% | 14 h 40 min |
| May 16 | 67°F | 42°F | 41% | 22% | 14 h 50 min |
| May 17 | 67°F | 42°F | 41% | 22% | 14 h 50 min |
| May 18 | 67°F | 43°F | 42% | 22% | 14 h 50 min |
| May 19 | 68°F | 43°F | 42% | 22% | 14 h 50 min |
| May 20 | 68°F | 43°F | 42% | 23% | 14 h 50 min |
| May 21 | 69°F | 44°F | 42% | 23% | 15 h |
| May 22 | 69°F | 44°F | 43% | 23% | 15 h |
| May 23 | 69°F | 45°F | 43% | 23% | 15 h |
| May 24 | 70°F | 45°F | 43% | 24% | 15 h |
| May 25 | 70°F | 45°F | 43% | 24% | 15 h |
| May 26 | 70°F | 46°F | 43% | 24% | 15 h |
| May 27 | 71°F | 46°F | 44% | 24% | 15 h 10 min |
| May 28 | 71°F | 46°F | 44% | 24% | 15 h 10 min |
| May 29 | 71°F | 47°F | 44% | 24% | 15 h 10 min |
| May 30 | 72°F | 47°F | 44% | 24% | 15 h 10 min |
| May 31 | 72°F | 47°F | 44% | 24% | 15 h 10 min |
- Normal high
- 67°FMay average
- Normal low
- 42°FMay average
- Precipitation
- 3.45 inmonth total
- Days with precipitation
- 130.01 inch or more
- Snowfall
- 1.5 inmonth total
- Days at 90°F or more
- 1
- Nights at 32°F or colder
- 4
- Daylight
- 14 h 10 min to 15 h 10 minMay 1 to May 31
- Days at 70°F or more
- 13
- Days at 80°F or more
- 4
- Sunshine
- 72%of clear-sky sunlight (NASA)
Source: NOAA NCEI 1991-2020 daily normals, station USW00024090; monthly normals. Daylight is computed from the place's latitude with NOAA's solar equations.
Does it rain or snow in Rapid City in May?
On a given May day the chance of 0.01 inch or more is 41% on average, highest around May 30 (44%). In all, 3.45 in falls on 13 days of a normal May, 1 of them with an inch or more.
In a normal May in Rapid City, 1 days reach 90°F, 4 nights fall to freezing and snowfall averages 1.5 inches.
Source: NOAA NCEI 1991-2020 daily and monthly normals, station USW00024090.
How humid and windy is Rapid City in May?
At 3 p.m. the normal temperature is 69°F with 48% relative humidity and a dew point of 49°F; at 6 a.m. it is 54°F with 77% humidity. The wind averages 10.5 mph, most often from the north-northeast in the afternoon. A dew point under 50°F feels dry.
| Time | Temperature | Dew point | Humidity | Wind | Clear or few clouds |
|---|---|---|---|---|---|
| 6 a.m. | 54°F | 47°F | 77% | 8.5 mph | 64% |
| 9 a.m. | 63°F | 48°F | 58% | 12.8 mph | 64% |
| noon | 68°F | 48°F | 49% | 13.6 mph | 56% |
| 3 p.m. | 69°F | 49°F | 48% | 13.5 mph | 57% |
| 6 p.m. | 66°F | 49°F | 55% | 11.9 mph | 62% |
| 9 p.m. | 57°F | 48°F | 73% | 8.2 mph | 63% |
Source: NOAA NCEI 1991-2020 hourly normals, station USW00024090. Hourly normals exist only for NOAA's first-order stations; a dash where NOAA publishes no value for that hour (the sky at some hours).
What are the records for May in Rapid City?
The warmest May temperature on Rapid City's official record (since 1942) is 98°F, on May 27, 1969; the coldest is 18°F, on May 1, 1950. The wettest May brought 8.18 in (1996); the snowiest, 13.0 inches (2015).
The May mean against the 1991-2020 normal of 54.1°F: 2021 52.8°F (−1.3), 2022 52.9°F (−1.2), 2023 59.1°F (+5.0), 2024 55.6°F (+1.5), 2025 57.4°F (+3.3), 2026 57.2°F (+3.1). 4 of 6 ran warmer than normal.
| May | Mean | Against normal | Precip. |
|---|---|---|---|
| 2021 | 52.8°F | −1.3°F | 2.48 in |
| 2022 | 52.9°F | −1.2°F | 2.58 in |
| 2023 | 59.1°F | +5.0°F | 5.66 in |
| 2024 | 55.6°F | +1.5°F | 1.68 in |
| 2025 | 57.4°F | +3.3°F | 2.08 in |
| 2026 | 57.2°F | +3.1°F | 3.85 in |
Source: records: ACIS, NWS threaded record RAPthr; recent months: ACIS, station USW00024090. Records and recent months use complete months only.
How does May in Rapid City compare across South Dakota?
Across the 100 places PlainClimate covers in South Dakota, May normal highs run from 60°F in Custer to 73°F in Wagner; Rapid City's is 67°F.
Source: NOAA NCEI 1991-2020 monthly normals for every station in the state.