Ralph (1 mi N), South Dakota climate: Climate normals at a NOAA weather station
Ralph (1 mi N)'s normal year runs from 7°F January nights to 86°F July afternoons, with 16.2 inches of precipitation a year. (NOAA 1991-2020 normals)
In metric: a yearly mean of 6.8°C, January lows of −14°C, July highs of 30°C, 411 mm of precipitation a year.
- NOAA stationRalph (1 mi N)
- Station IDUSC00396907
- Location45.78°N 103.07°W
- Elevation2,790 ft (850 m)
On October 23, the normal high in Ralph (1 mi N) is 54°F and the normal low 28°F, and the chance of measurable rain or snow is 18%.
Normals describe a typical year at the station, not a forecast. The National Weather Service forecast for Ralph (1 mi N).
- Jan 30° 7°
- Feb 33° 10°
- Mar 45° 20°
- Apr 57° 29°
- May 68° 40°
- Jun 77° 50°
- Jul 86° 56°
- Aug 86° 54°
- Sep 76° 44°
- Oct 59° 31°
- Nov 43° 20°
- Dec 33° 10°
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 Ralph (1 mi N) each month?
July is the warmest month, with normal highs of 86°F; January the coldest, with normal lows of 7°F. The most precipitation falls in June (3.24 in), the least in January (0.49 in).
| Month | High | Low | Mean | Precip. | Wet days | 90°F days | Freezing nights | Daylight |
|---|---|---|---|---|---|---|---|---|
| January | 30°F | 7°F | 18.8°F | 0.49 | 5 | <1 | 31 | 9 h |
| February | 33°F | 10°F | 21.8°F | 0.71 | 6 | <1 | 28 | 10 h 20 min |
| March | 45°F | 20°F | 32.5°F | 0.66 | 6 | <1 | 28 | 11 h 50 min |
| April | 57°F | 29°F | 42.8°F | 1.33 | 7 | <1 | 19 | 13 h 30 min |
| May | 68°F | 40°F | 53.6°F | 2.74 | 8 | <1 | 6 | 14 h 50 min |
| June | 77°F | 50°F | 63.6°F | 3.24 | 10 | 1 | <1 | 15 h 40 min |
| July | 86°F | 56°F | 70.7°F | 2.22 | 9 | 9 | <1 | 15 h 20 min |
| August | 86°F | 54°F | 69.5°F | 1.39 | 5 | 11 | <1 | 14 h 10 min |
| September | 76°F | 44°F | 59.6°F | 1.18 | 5 | 3 | 4 | 12 h 40 min |
| October | 59°F | 31°F | 44.9°F | 1.19 | 6 | <1 | 17 | 11 h |
| November | 43°F | 20°F | 31.4°F | 0.52 | 6 | <1 | 28 | 9 h 30 min |
| December | 33°F | 10°F | 21.2°F | 0.52 | 4 | <1 | 31 | 8 h 40 min |
| Year (annual) | 58°F | 31°F | 44.2°F | 16.19 | 75 | 25 | 193 |
The same normals in °C and millimetres
| Month | High | Low | Mean | Precip. |
|---|---|---|---|---|
| January | −1°C | −14°C | −7.3°C | 12 mm |
| February | 1°C | −12°C | −5.7°C | 18 mm |
| March | 7°C | −7°C | 0.3°C | 17 mm |
| April | 14°C | −2°C | 6.0°C | 34 mm |
| May | 20°C | 4°C | 12.0°C | 70 mm |
| June | 25°C | 10°C | 17.6°C | 82 mm |
| July | 30°C | 13°C | 21.5°C | 56 mm |
| August | 30°C | 12°C | 20.8°C | 35 mm |
| September | 24°C | 6°C | 15.3°C | 30 mm |
| October | 15°C | 0°C | 7.2°C | 30 mm |
| November | 6°C | −7°C | −0.3°C | 13 mm |
| December | 0°C | −12°C | −6.0°C | 13 mm |
NOAA publishes no 1991-2020 snowfall normal for this station, and no record within 25 miles keeps one, so snow is left out here rather than estimated.
Source: NOAA NCEI 1991-2020 monthly normals, station USC00396907; 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 Ralph (1 mi N)?
Normal highs sit between 65°F and 85°F in May, June and September. Of those, September has the fewest days with rain (5).
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 USC00396907.
When is the last frost at Ralph (1 mi N)?
In Ralph (1 mi N), the last spring frost (32°F) comes after May 18 in half of years and after May 31 in one year in ten; the first autumn frost comes before September 23 in half of years and before September 8 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 181 year in 10 after May 31; 9 in 10 after May 7
- First autumn frost, half of years before
- September 231 year in 10 before September 8; 9 in 10 before October 6
NOAA puts the median frost-free season at 126 days, and the season without a hard freeze (28°F) at 146 days.
A hard freeze (28°F) comes after May 8 in half of springs and before October 1 in half of autumns.
The USDA's 2023 Plant Hardiness Zone Map puts Ralph (1 mi N) in zone 4b in ZIP code 57650, 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 USC00396907; 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 Ralph (1 mi N)?
In a normal year in Ralph (1 mi N), 25 days a year reach 90°F (3 of them 100°F or more), 193 nights fall to 32°F or colder and 75 days bring measurable precipitation.
- Days at 90°F or more
- 25a normal year
- Days at 100°F or more
- 3a normal year
- Nights at 32°F or colder
- 193a normal year
- Days that stay below freezing
- 58high of 32°F or less
- Days with 0.01 inch of precipitation
- 75a normal year
The highest temperature in this station's record (since 1941) is 112°F, on July 7, 1981; the lowest is −42°F, on January 21, 1949.
The wettest calendar year on that record is 1977, with 22.44 in; the snowiest season is 1985–86, with 69.7 inches.
Source: NOAA NCEI 1991-2020 annual normals, station USC00396907; records: ACIS (NOAA Regional Climate Centers), station USC00396907. Records use complete months only; a month missing more than three days is left out.
How sunny is it at Ralph (1 mi N)?
Over a year 79% of the sunlight that would reach the ground under clear skies gets through the clouds at Ralph (1 mi N), 4.2 kWh per square metre a day. July is the sunniest month (87%) and April the cloudiest (73%).
| Month | Share of clear-sky sunshine | Sunshine, kWh/m² a day |
|---|---|---|
| January | 77% | 1.9 |
| February | 79% | 2.9 |
| March | 74% | 3.9 |
| April | 73% | 5.0 |
| May | 74% | 6.0 |
| June | 80% | 6.8 |
| July | 87% | 7.0 |
| August | 86% | 6.0 |
| September | 82% | 4.5 |
| October | 75% | 3.0 |
| November | 75% | 2.0 |
| December | 73% | 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 Ralph (1 mi N) record?
A normal year at Ralph (1 mi N) brings 8,033 heating degree days, 50% more than the median U.S. place (5,373), and 489 cooling degree days, 46% fewer than the median (908). Eight months need 300 or more heating degree days, a monthly mean of about 55°F or colder. For gardens and crops, NOAA counts 2,238 growing degree days a year above 50°F.
| Month | Heating | Cooling |
|---|---|---|
| January | 1,432 | 0 |
| February | 1,209 | 0 |
| March | 1,008 | 0 |
| April | 666 | 0 |
| May | 362 | 9 |
| June | 105 | 62 |
| July | 24 | 200 |
| August | 34 | 175 |
| September | 203 | 42 |
| October | 626 | 1 |
| November | 1,006 | 0 |
| December | 1,357 | 0 |
| Year (annual) | 8,033 | 489 |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00396907. 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.
How does Ralph (1 mi N)'s climate compare?
Ralph (1 mi N) is warmer than 29 of the 100 places with their own NOAA record in South Dakota, and wetter than 4. Across the 7,247 U.S. stations with normals, its annual mean of 44.2°F is warmer than 16%.
In the Köppen classification computed from these normals, Ralph (1 mi N) is BSk: cold semi-arid steppe. 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 Ralph (1 mi N) 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.
- Reeder, ND123 people · 23 mi N
- Gascoyne, ND20 people · 23 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 Ralph (1 mi N)'s climate
What is the coldest month at Ralph (1 mi N)?
January, with a normal high of 30°F and a normal low of 7°F. The warmest is July (86°F by day, 56°F at night).
What is the rainiest month at Ralph (1 mi N)?
June, with 3.24 in of precipitation in a normal year; the driest is January with 0.49 in.
What plant hardiness zone is Ralph (1 mi N) in?
The USDA's 2023 map puts Ralph (1 mi N) in zone 4b in ZIP code 57650, the nearest ZIP area.
How late can frost come at Ralph (1 mi N)?
In half of years the last 32°F night comes after May 18; in one year in ten it comes after May 31. Waiting until May 31 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
- Lodgepole (5 mi SW), SD13 miles from this station, 41.1°F a year
- Ludlow (3 mi SSE), SD15 miles from this station, 44.0°F a year
- Antelope Ranger Station, SD22 miles from this station, 43.4°F a year
- Hettinger, ND25 miles from this station, 42.4°F a year
- Compare two placesMonth by month, side by side
Download these normals (CSV) · JSON · How these figures are made