Roscoe, South Dakota climate: Normal weather by month, frost dates and records
Roscoe's normal year runs from 3°F January nights to 83°F July afternoons, with 21.4 inches of precipitation and 47 inches of snow a year. (NOAA 1991-2020 normals)
In metric: a yearly mean of 5.9°C, January lows of −16°C, July highs of 28°C, 544 mm of precipitation a year.
- NOAA stationRoscoe
- Station IDUSC00397277
- Location45.45°N 99.34°W
- Elevation1,835 ft (559 m)
- Population279
On October 22, the normal high in Roscoe is 53°F and the normal low 31°F, and the chance of measurable rain or snow is 23%.
Normals describe a typical year at the station, not a forecast. The National Weather Service forecast for Roscoe.
- Jan 21° 3°
- Feb 26° 7°
- Mar 39° 18°
- Apr 54° 30°
- May 67° 43°
- Jun 77° 54°
- Jul 83° 59°
- Aug 81° 56°
- Sep 73° 47°
- Oct 57° 33°
- Nov 40° 20°
- Dec 26° 9°
Each month: normal high (large) and low, °F. Fill: the month's normal mean, colder blue to hotter red.
What is the weather like in Roscoe each month?
July is the warmest month, with normal highs of 83°F; January the coldest, with normal lows of 3°F. The most precipitation falls in June (3.70 in), the least in January (0.54 in).
| Month | High | Low | Mean | Precip. | Snow | Wet days | 90°F days | Freezing nights | Daylight |
|---|---|---|---|---|---|---|---|---|---|
| January | 21°F | 3°F | 12.3°F | 0.54 | 8.1 | 7 | <1 | 31 | 9 h |
| February | 26°F | 7°F | 16.4°F | 0.66 | 8.8 | 7 | <1 | 28 | 10 h 20 min |
| March | 39°F | 18°F | 28.3°F | 0.95 | 7.3 | 7 | <1 | 29 | 11 h 50 min |
| April | 54°F | 30°F | 42.1°F | 1.84 | 5.8 | 8 | <1 | 18 | 13 h 30 min |
| May | 67°F | 43°F | 54.9°F | 3.16 | 0.1 | 11 | 1 | 3 | 14 h 50 min |
| June | 77°F | 54°F | 65.5°F | 3.70 | 0.0 | 12 | 2 | <1 | 15 h 40 min |
| July | 83°F | 59°F | 70.8°F | 3.24 | 0.0 | 10 | 6 | <1 | 15 h 20 min |
| August | 81°F | 56°F | 68.8°F | 2.30 | 0.0 | 8 | 5 | <1 | 14 h 10 min |
| September | 73°F | 47°F | 59.6°F | 1.91 | 0.0 | 7 | 1 | 1 | 12 h 40 min |
| October | 57°F | 33°F | 45.0°F | 1.79 | 2.3 | 7 | <1 | 14 | 11 h |
| November | 40°F | 20°F | 29.9°F | 0.69 | 5.9 | 6 | <1 | 27 | 9 h 30 min |
| December | 26°F | 9°F | 17.8°F | 0.64 | 8.7 | 6 | <1 | 31 | 8 h 40 min |
| Year (annual) | 54°F | 32°F | 42.6°F | 21.42 | 47.0 | 95 | 14 | 182 |
The same normals in °C and millimetres
| Month | High | Low | Mean | Precip. | Snow |
|---|---|---|---|---|---|
| January | −6°C | −16°C | −10.9°C | 14 mm | 21 cm |
| February | −3°C | −14°C | −8.7°C | 17 mm | 22 cm |
| March | 4°C | −8°C | −2.1°C | 24 mm | 19 cm |
| April | 12°C | −1°C | 5.6°C | 47 mm | 15 cm |
| May | 19°C | 6°C | 12.7°C | 80 mm | 0 cm |
| June | 25°C | 12°C | 18.6°C | 94 mm | 0 cm |
| July | 28°C | 15°C | 21.6°C | 82 mm | 0 cm |
| August | 27°C | 13°C | 20.4°C | 58 mm | 0 cm |
| September | 23°C | 8°C | 15.3°C | 49 mm | 0 cm |
| October | 14°C | 1°C | 7.2°C | 45 mm | 6 cm |
| November | 4°C | −7°C | −1.2°C | 18 mm | 15 cm |
| December | −3°C | −13°C | −7.9°C | 16 mm | 22 cm |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00397277; 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.
When is the best weather to visit Roscoe?
Normal highs sit between 65°F and 85°F in May, June, July, August and September. Of those, September has the fewest days with rain (7).
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 USC00397277.
When is the last frost in Roscoe?
In Roscoe, the last spring frost (32°F) comes after May 7 in half of years and after May 20 in one year in ten; the first autumn frost comes before October 3 in half of years and before September 19 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 71 year in 10 after May 20; 9 in 10 after April 24
- First autumn frost, half of years before
- October 31 year in 10 before September 19; 9 in 10 before October 16
NOAA puts the median frost-free season at 148 days, and the season without a hard freeze (28°F) at 166 days.
A hard freeze (28°F) comes after April 29 in half of springs and before October 12 in half of autumns.
The USDA's 2023 Plant Hardiness Zone Map puts Roscoe in zone 4b in ZIP code 57471, the nearest ZIP area. By the map's own method, the average of each year's coldest night over 1991-2020, Roscoe's NOAA station is in zone 4b: the coldest night of a typical year reaches −22°F (30 complete years).
Frost dates for every NOAA station in South Dakota · Frost dates by ZIP code
Source: NOAA NCEI 1991-2020 annual normals (frost probabilities), station USC00397277; USDA 2023 Plant Hardiness Zone Map, ZIP listings: PRISM Group, Oregon State University, https://prism.oregonstate.edu, accessed October 8, 2026; the station zone: ACIS daily lows, 1991-2020. 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 in Roscoe?
In a normal year in Roscoe, 14 days a year reach 90°F (1 of them 100°F or more), 182 nights fall to 32°F or colder and 95 days bring measurable precipitation.
- Days at 90°F or more
- 14a normal year
- Days at 100°F or more
- 1a normal year
- Nights at 32°F or colder
- 182a normal year
- Days that stay below freezing
- 86high of 32°F or less
- Days with 0.01 inch of precipitation
- 95a normal year
- Days with 1 inch of snow or more
- 14a normal year
The highest temperature in this station's record (since 1935) is 112°F, on July 16, 2006; the lowest is −37°F, on January 15, 1972.
The wettest calendar year on that record is 2019, with 29.52 in; the snowiest season is 2010–11, with 98.1 inches.
Source: NOAA NCEI 1991-2020 annual normals, station USC00397277; records: ACIS (NOAA Regional Climate Centers), station USC00397277. Records use complete months only; a month missing more than three days is left out.
How sunny is Roscoe?
Over a year 78% of the sunlight that would reach the ground under clear skies gets through the clouds in the area around Roscoe, 4.1 kWh per square metre a day. July is the sunniest month (85%) and December the cloudiest (70%).
| Month | Share of clear-sky sunshine | Sunshine, kWh/m² a day |
|---|---|---|
| January | 79% | 1.9 |
| February | 81% | 3.0 |
| March | 75% | 4.0 |
| April | 73% | 5.0 |
| May | 73% | 5.8 |
| June | 79% | 6.5 |
| July | 85% | 6.8 |
| August | 83% | 5.6 |
| September | 79% | 4.3 |
| October | 72% | 2.8 |
| November | 73% | 1.9 |
| December | 70% | 1.4 |
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 much heating and cooling does Roscoe need?
A normal year in Roscoe brings 8,624 heating degree days, 61% more than the median U.S. place (5,373), and 503 cooling degree days, 45% 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 2,318 growing degree days a year above 50°F.
| Month | Heating | Cooling |
|---|---|---|
| January | 1,634 | 0 |
| February | 1,361 | 0 |
| March | 1,138 | 0 |
| April | 689 | 0 |
| May | 329 | 18 |
| June | 76 | 90 |
| July | 19 | 197 |
| August | 35 | 153 |
| September | 205 | 43 |
| October | 622 | 2 |
| November | 1,055 | 0 |
| December | 1,463 | 0 |
| Year (annual) | 8,624 | 503 |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00397277. 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.
Has Roscoe been warmer than normal lately?
2022 averaged 41.0°F, 1.6°F below the 1991-2020 normal of 42.6°F. 1 of the 2 complete years since 2021 ran warmer than the normal.
| Year | Mean | Against normal | Precip. | Snow |
|---|---|---|---|---|
| 2021 | 45.4°F | +2.8°F | 18.65 | 19.0 |
| 2022 | 41.0°F | −1.6°F | – | – |
Over 49 complete years from 1949 to 2021, the station's annual mean temperature rose at a fitted 4.0°F per century (+0.22°C per decade). A fitted rate summarizes the whole record; single years swing well above and below it.
Source: observed years: ACIS, station USC00397277; trend: NOAA GHCN-Monthly v4. A year counts only with all twelve months complete.
How does Roscoe's climate compare?
Roscoe is warmer than 5 of the other 99 places with their own NOAA record in South Dakota, and wetter than 38. Across the 7,247 U.S. stations with normals, its annual mean of 42.6°F is warmer than 11%.
In the Köppen classification computed from these normals, Roscoe is Dfb: continental, no dry season, warm 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 Roscoe share this climate record?
3 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.
- Bowdle, SD472 people · 16 mi W
- Hosmer, SD159 people · 11 mi NW
- Onaka, SD14 people · 19 mi S
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 Roscoe's climate
What is the coldest month in Roscoe?
January, with a normal high of 21°F and a normal low of 3°F. The warmest is July (83°F by day, 59°F at night).
Does it snow in Roscoe?
Yes: 47 inches in a normal year, falling on 33 days with 0.1 inch or more, the most in February (8.8 inches).
What is the rainiest month in Roscoe?
June, with 3.70 in of precipitation in a normal year; the driest is January with 0.54 in.
What plant hardiness zone is Roscoe in?
The USDA's 2023 map puts Roscoe in zone 4b in ZIP code 57471, the nearest ZIP area. By the same method at Roscoe's NOAA station, the coldest night of a typical year reaches −22°F (30 years, 1991-2020): zone 4b.
How late can frost come in Roscoe?
In half of years the last 32°F night comes after May 7; in one year in ten it comes after May 20. Waiting until May 20 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
- Ipswich, SD14 miles from this station, 43.7°F a year
- Aberdeen (35 mi WNW), SD21 miles from this station, 41.9°F a year
- Eureka, SD25 miles from this station, 41.8°F a year
- Leola, SD27 miles from this station, 42.2°F a year
- Compare two placesMonth by month, side by side
Download these normals (CSV) · JSON · How these figures are made