Oahe Dam, South Dakota climate: Climate normals at a NOAA weather station
Oahe Dam's normal year runs from 8°F January nights to 89°F July afternoons, with 19.3 inches of precipitation a year. (NOAA 1991-2020 normals)
In metric: a yearly mean of 8.3°C, January lows of −13°C, July highs of 32°C, 489 mm of precipitation a year.
- NOAA stationOahe Dam
- Station IDUSC00396170
- Location44.44°N 100.42°W
- Elevation1,663 ft (507 m)
On October 24, the normal high in Oahe Dam is 58°F and the normal low 33°F.
Normals describe a typical year at the station, not a forecast. The National Weather Service forecast for Oahe Dam.
- Jan 31° 8°
- Feb 34° 11°
- Mar 46° 21°
- Apr 58° 32°
- May 70° 44°
- Jun 80° 55°
- Jul 89° 61°
- Aug 87° 59°
- Sep 78° 49°
- Oct 62° 36°
- Nov 47° 24°
- Dec 34° 12°
Each month: normal high (large) and low, °F. Fill: the month's normal mean, colder blue to hotter red.
What is the weather like at Oahe Dam each month?
July is the warmest month, with normal highs of 89°F; January the coldest, with normal lows of 8°F. The most precipitation falls in June (3.27 in), the least in January (0.44 in).
| Month | High | Low | Mean | Precip. | Wet days | 90°F days | Freezing nights | Daylight |
|---|---|---|---|---|---|---|---|---|
| January | 31°F | 8°F | 19.2°F | 0.44 | – | <1 | 31 | 9 h 10 min |
| February | 34°F | 11°F | 22.5°F | 0.64 | – | <1 | 28 | 10 h 30 min |
| March | 46°F | 21°F | 33.3°F | 0.79 | – | <1 | 26 | 11 h 50 min |
| April | 58°F | 32°F | 44.9°F | 1.78 | – | <1 | 15 | 13 h 30 min |
| May | 70°F | 44°F | 56.9°F | 3.17 | – | 1 | 3 | 14 h 50 min |
| June | 80°F | 55°F | 67.5°F | 3.27 | – | 5 | <1 | 15 h 30 min |
| July | 89°F | 61°F | 74.8°F | 2.58 | – | 14 | <1 | 15 h 10 min |
| August | 87°F | 59°F | 72.9°F | 2.27 | – | 14 | <1 | 14 h 10 min |
| September | 78°F | 49°F | 63.6°F | 1.61 | – | 6 | 1 | 12 h 40 min |
| October | 62°F | 36°F | 49.3°F | 1.64 | – | 1 | 11 | 11 h |
| November | 47°F | 24°F | 35.2°F | 0.55 | – | <1 | 26 | 9 h 40 min |
| December | 34°F | 12°F | 23.1°F | 0.53 | – | <1 | 30 | 8 h 50 min |
| Year (annual) | 60°F | 34°F | 46.9°F | 19.27 | – | 41 | 169 |
The same normals in °C and millimetres
| Month | High | Low | Mean | Precip. |
|---|---|---|---|---|
| January | −1°C | −13°C | −7.1°C | 11 mm |
| February | 1°C | −12°C | −5.3°C | 16 mm |
| March | 8°C | −6°C | 0.7°C | 20 mm |
| April | 14°C | 0°C | 7.2°C | 45 mm |
| May | 21°C | 7°C | 13.8°C | 81 mm |
| June | 27°C | 13°C | 19.7°C | 83 mm |
| July | 32°C | 16°C | 23.8°C | 66 mm |
| August | 31°C | 15°C | 22.7°C | 58 mm |
| September | 26°C | 10°C | 17.6°C | 41 mm |
| October | 17°C | 2°C | 9.6°C | 42 mm |
| November | 8°C | −5°C | 1.8°C | 14 mm |
| December | 1°C | −11°C | −4.9°C | 13 mm |
NOAA publishes no 1991-2020 snowfall normal for this station. The nearest record that keeps one, Pierre (8 miles away), gets 37 inches of snow in a normal year; elevation and distance can change that.
Source: NOAA NCEI 1991-2020 monthly normals, station USC00396170; annual normals. Wet days: 0.01 inch or more; 90°F days and freezing nights: NOAA's day counts. Daylight: sunrise to sunset on the 15th, computed from the latitude.
Which months are mildest at Oahe Dam?
Normal highs sit between 65°F and 85°F in May, June and September.
That is a measurement, not a recommendation: it counts the months whose normal afternoon high sits between 65°F and 85°F, where a light layer is enough by day.
Source: NOAA NCEI 1991-2020 monthly normals, station USC00396170.
When is the last frost at Oahe Dam?
In Oahe Dam, the last spring frost (32°F) comes after May 6 in half of years and after May 19 in one year in ten; the first autumn frost comes before October 5 in half of years and before September 23 in one year in ten.
Frost-free in half of yearsFrost in 1 to 9 years out of 10Frost most years
- Last spring frost, half of years after
- May 61 year in 10 after May 19; 9 in 10 after April 23
- First autumn frost, half of years before
- October 51 year in 10 before September 23; 9 in 10 before October 18
NOAA puts the median frost-free season at 152 days, and the season without a hard freeze (28°F) at 170 days.
A hard freeze (28°F) comes after April 27 in half of springs and before October 15 in half of autumns.
The USDA's 2023 Plant Hardiness Zone Map puts Oahe Dam in zone 4b in ZIP code 57501, the nearest ZIP area.
Frost dates for every NOAA station in South Dakota · Frost dates by ZIP code
Source: NOAA NCEI 1991-2020 annual normals (frost probabilities), station USC00396170; USDA 2023 Plant Hardiness Zone Map, ZIP listings: PRISM Group, Oregon State University, https://prism.oregonstate.edu, accessed October 8, 2026. A 10% date means one year in ten has a frost after it in spring or before it in autumn.
How hot and how cold does it get at Oahe Dam?
In a normal year in Oahe Dam, 41 days a year reach 90°F (8 of them 100°F or more) and 169 nights fall to 32°F or colder.
- Days at 90°F or more
- 41a normal year
- Days at 100°F or more
- 8a normal year
- Nights at 32°F or colder
- 169a normal year
- Days that stay below freezing
- 52high of 32°F or less
The highest temperature in this station's record (since 1960) is 114°F, on June 24, 1988; the lowest is −31°F, on December 22, 1983.
The wettest calendar year on that record is 1977, with 20.37 in; the snowiest season is 1964–65, with 29.5 inches.
Source: NOAA NCEI 1991-2020 annual normals, station USC00396170; records: ACIS (NOAA Regional Climate Centers), station USC00396170. Records use complete months only; a month missing more than three days is left out.
How sunny is it at Oahe Dam?
Over a year 78% of the sunlight that would reach the ground under clear skies gets through the clouds at Oahe Dam, 4.2 kWh per square metre a day. July is the sunniest month (87%) and December the cloudiest (70%).
| Month | Share of clear-sky sunshine | Sunshine, kWh/m² a day |
|---|---|---|
| January | 75% | 1.9 |
| February | 75% | 2.9 |
| March | 73% | 3.9 |
| April | 72% | 5.0 |
| May | 74% | 6.0 |
| June | 81% | 6.8 |
| July | 87% | 6.9 |
| August | 84% | 5.8 |
| September | 81% | 4.5 |
| October | 74% | 3.0 |
| November | 74% | 2.0 |
| December | 70% | 1.5 |
Source: NASA POWER solar climatology, 2001-2020 (CERES SYN1deg). Satellite-based, for the 1-degree cell (about 100 km across) around the station, so it describes the area rather than the airport.
How many heating and cooling degree days does Oahe Dam record?
A normal year at Oahe Dam brings 7,361 heating degree days, 37% more than the median U.S. place (5,373), and 809 cooling degree days, 11% fewer than the median (908). Seven months need 300 or more heating degree days, a monthly mean of about 55°F or colder. For gardens and crops, NOAA counts 2,849 growing degree days a year above 50°F.
| Month | Heating | Cooling |
|---|---|---|
| January | 1,421 | 0 |
| February | 1,190 | 0 |
| March | 984 | 0 |
| April | 604 | 1 |
| May | 275 | 22 |
| June | 54 | 128 |
| July | 6 | 310 |
| August | 13 | 258 |
| September | 128 | 85 |
| October | 494 | 5 |
| November | 894 | 0 |
| December | 1,299 | 0 |
| Year (annual) | 7,361 | 809 |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00396170. A degree day is one degree of a day's mean temperature below 65°F (heating) or above it (cooling); utilities use them to estimate energy use.
Have recent years at Oahe Dam been warmer than normal?
2025 averaged 47.7°F, 0.8°F above the 1991-2020 normal of 46.9°F. 4 of the 4 complete years since 2022 ran warmer than the normal.
| Year | Mean | Against normal | Precip. |
|---|---|---|---|
| 2022 | 47.5°F | +0.6°F | 14.12 |
| 2023 | 48.1°F | +1.2°F | – |
| 2024 | 48.7°F | +1.8°F | – |
| 2025 | 47.7°F | +0.8°F | – |
Over 72 complete years from 1910 to 2025, the station's annual mean temperature rose at a fitted 1.2°F per century (+0.06°C per decade). A fitted rate summarizes the whole record; single years swing well above and below it.
Source: observed years: ACIS, station USC00396170; trend: NOAA GHCN-Monthly v4. A year counts only with all twelve months complete.
How does Oahe Dam's climate compare?
Oahe Dam is warmer than 68 of the 100 places with their own NOAA record in South Dakota, and wetter than 21. Across the 7,247 U.S. stations with normals, its annual mean of 46.9°F is warmer than 27%.
In the Köppen classification computed from these normals, Oahe Dam is Dfa: continental, no dry season, hot summer. What the classes mean.
Places with the most similar year elsewhere
Measured month by month on the normal high, low and precipitation, among places of 20,000 or more people in other states:
Source: NOAA NCEI 1991-2020 normals for every station PlainClimate covers. Similarity: the root-mean-square difference of the 36 monthly figures, precipitation weighted so an inch counts like 6°F.
Which places near Oahe Dam share this climate record?
2 places have no NOAA station with 1991-2020 normals of their own, and this station is the nearest full record. A place's own climate can differ from these figures, by several degrees where it sits much higher or lower than the station, nearer the coast, or inside a large city's heat; for the larger places the next nearest records are named with their yearly mean, so the spread around them is visible, and places of 50,000 or more have their own page with NOAA's gridded normals.
- Oahe Acres, SD443 people · 4 mi NE
- Cow Creek, SD64 people · 8 mi N
Source: Census Bureau 2024 Gazetteer (place centers) and Vintage 2024 population estimates. Distance and direction from the station to each place's center.
Questions about Oahe Dam's climate
What is the coldest month at Oahe Dam?
January, with a normal high of 31°F and a normal low of 8°F. The warmest is July (89°F by day, 61°F at night).
Does it snow at Oahe Dam?
Yes. NOAA publishes no 1991-2020 snowfall normal for the station; the nearest record that keeps one, Pierre (8 miles away), records 37 inches of snow in a normal year.
What is the rainiest month at Oahe Dam?
June, with 3.27 in of precipitation in a normal year; the driest is January with 0.44 in.
What plant hardiness zone is Oahe Dam in?
The USDA's 2023 map puts Oahe Dam in zone 4b in ZIP code 57501, the nearest ZIP area.
How late can frost come at Oahe Dam?
In half of years the last 32°F night comes after May 6; in one year in ten it comes after May 19. Waiting until May 19 leaves about a one-in-ten chance of a later frost.
Nearby and next
- South Dakota climateThe statewide normals and every place in the state
- Pierre, SD7 miles from this station, 47.0°F a year
- Fort Pierre (17 mi WSW), SD18 miles from this station, 47.7°F a year
- Onida, SD24 miles from this station, 46.0°F a year
- Mission Ridge (5 mi NW), SD28 miles from this station, 46.2°F a year
- Compare two placesMonth by month, side by side
Download these normals (CSV) · JSON · How these figures are made