Harrington, South Dakota climate: Climate normals at a NOAA weather station
Harrington's normal year runs from 12°F January nights to 87°F July afternoons, with 21.9 inches of precipitation and 47 inches of snow a year. (NOAA 1991-2020 normals)
In metric: a yearly mean of 8.7°C, January lows of −11°C, July highs of 30°C, 555 mm of precipitation a year.
- NOAA stationHarrington
- Station IDUSC00393574
- Location43.16°N 101.26°W
- Elevation2,980 ft (908 m)
On October 22, the normal high in Harrington is 59°F and the normal low 32°F, and the chance of measurable rain or snow is 17%.
Normals describe a typical year at the station, not a forecast. The National Weather Service forecast for Harrington.
- Jan 35° 12°
- Feb 38° 14°
- Mar 50° 23°
- Apr 59° 32°
- May 69° 43°
- Jun 79° 54°
- Jul 87° 60°
- Aug 86° 58°
- Sep 78° 49°
- Oct 62° 35°
- Nov 48° 22°
- Dec 37° 13°
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 Harrington each month?
July is the warmest month, with normal highs of 87°F; January the coldest, with normal lows of 12°F. The most precipitation falls in June (3.99 in), the least in January (0.52 in).
| Month | High | Low | Mean | Precip. | Snow | Wet days | 90°F days | Freezing nights | Daylight |
|---|---|---|---|---|---|---|---|---|---|
| January | 35°F | 12°F | 23.6°F | 0.52 | 7.2 | 5 | <1 | 31 | 9 h 20 min |
| February | 38°F | 14°F | 26.3°F | 0.74 | 7.5 | 6 | <1 | 27 | 10 h 30 min |
| March | 50°F | 23°F | 36.4°F | 1.26 | 8.4 | 6 | <1 | 25 | 11 h 50 min |
| April | 59°F | 32°F | 45.4°F | 2.77 | 6.7 | 9 | <1 | 15 | 13 h 20 min |
| May | 69°F | 43°F | 56.3°F | 3.68 | 0.2 | 9 | 1 | 3 | 14 h 40 min |
| June | 79°F | 54°F | 66.5°F | 3.99 | 0.0 | 10 | 3 | <1 | 15 h 20 min |
| July | 87°F | 60°F | 73.2°F | 2.14 | 0.0 | 8 | 11 | <1 | 15 h 10 min |
| August | 86°F | 58°F | 71.5°F | 2.04 | 0.0 | 7 | 11 | <1 | 14 h |
| September | 78°F | 49°F | 63.2°F | 1.58 | 0.1 | 5 | 5 | 1 | 12 h 30 min |
| October | 62°F | 35°F | 48.3°F | 1.76 | 2.8 | 6 | <1 | 12 | 11 h 10 min |
| November | 48°F | 22°F | 35.0°F | 0.79 | 8.7 | 5 | <1 | 27 | 9 h 50 min |
| December | 37°F | 13°F | 25.1°F | 0.60 | 5.6 | 4 | <1 | 30 | 9 h |
| Year (annual) | 61°F | 35°F | 47.6°F | 21.87 | 47.2 | 79 | 32 | 171 |
The same normals in °C and millimetres
| Month | High | Low | Mean | Precip. | Snow |
|---|---|---|---|---|---|
| January | 2°C | −11°C | −4.7°C | 13 mm | 18 cm |
| February | 3°C | −10°C | −3.2°C | 19 mm | 19 cm |
| March | 10°C | −5°C | 2.4°C | 32 mm | 21 cm |
| April | 15°C | 0°C | 7.4°C | 70 mm | 17 cm |
| May | 21°C | 6°C | 13.5°C | 93 mm | 1 cm |
| June | 26°C | 12°C | 19.2°C | 101 mm | 0 cm |
| July | 30°C | 15°C | 22.9°C | 54 mm | 0 cm |
| August | 30°C | 14°C | 21.9°C | 52 mm | 0 cm |
| September | 26°C | 9°C | 17.3°C | 40 mm | 0 cm |
| October | 17°C | 2°C | 9.1°C | 45 mm | 7 cm |
| November | 9°C | −5°C | 1.7°C | 20 mm | 22 cm |
| December | 3°C | −10°C | −3.8°C | 15 mm | 14 cm |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00393574; 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 Harrington?
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 USC00393574.
When is the last frost at Harrington?
In Harrington, the last spring frost (32°F) comes after May 11 in half of years and after May 24 in one year in ten; the first autumn frost comes before October 1 in half of years and before September 18 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 111 year in 10 after May 24; 9 in 10 after April 29
- First autumn frost, half of years before
- October 11 year in 10 before September 18; 9 in 10 before October 14
NOAA puts the median frost-free season at 143 days, and the season without a hard freeze (28°F) at 161 days.
A hard freeze (28°F) comes after May 1 in half of springs and before October 10 in half of autumns.
The USDA's 2023 Plant Hardiness Zone Map puts Harrington in zone 5a in ZIP code 57574, the nearest ZIP area. By the map's own method, the average of each year's coldest night over 1991-2020, the station is in zone 4b: the coldest night of a typical year reaches −21°F (16 complete years); the map interpolates between stations and terrain, so the station and the ZIP area can differ by half a zone.
Frost dates for every NOAA station in South Dakota · Frost dates by ZIP code
Source: NOAA NCEI 1991-2020 annual normals (frost probabilities), station USC00393574; 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 at Harrington?
In a normal year in Harrington, 32 days a year reach 90°F (4 of them 100°F or more), 171 nights fall to 32°F or colder and 79 days bring measurable precipitation.
- Days at 90°F or more
- 32a normal year
- Days at 100°F or more
- 4a normal year
- Nights at 32°F or colder
- 171a normal year
- Days that stay below freezing
- 42high of 32°F or less
- Days with 0.01 inch of precipitation
- 79a normal year
- Days with 1 inch of snow or more
- 21a normal year
The highest temperature in this station's record (since 1960) is 110°F, on July 25, 2003; the lowest is −38°F, on December 21, 1983.
The wettest calendar year on that record is 1993, with 28.68 in; the snowiest season is 1976–77, with 74.5 inches.
Source: NOAA NCEI 1991-2020 annual normals, station USC00393574; records: ACIS (NOAA Regional Climate Centers), station USC00393574. Records use complete months only; a month missing more than three days is left out.
How sunny is it at Harrington?
Over a year 79% of the sunlight that would reach the ground under clear skies gets through the clouds at Harrington, 4.3 kWh per square metre a day. July is the sunniest month (87%) and April the cloudiest (72%).
| Month | Share of clear-sky sunshine | Sunshine, kWh/m² a day |
|---|---|---|
| January | 75% | 2.0 |
| February | 74% | 2.9 |
| March | 72% | 4.0 |
| April | 72% | 5.0 |
| May | 75% | 6.1 |
| June | 82% | 6.9 |
| July | 87% | 7.0 |
| August | 86% | 6.0 |
| September | 83% | 4.8 |
| October | 76% | 3.2 |
| November | 76% | 2.2 |
| December | 72% | 1.7 |
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 Harrington record?
A normal year at Harrington brings 7,029 heating degree days, 31% more than the median U.S. place (5,373), and 708 cooling degree days, 22% 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 2,717 growing degree days a year above 50°F.
| Month | Heating | Cooling |
|---|---|---|
| January | 1,283 | 0 |
| February | 1,083 | 0 |
| March | 888 | 0 |
| April | 588 | 1 |
| May | 289 | 20 |
| June | 68 | 112 |
| July | 12 | 266 |
| August | 19 | 220 |
| September | 139 | 85 |
| October | 521 | 4 |
| November | 900 | 0 |
| December | 1,238 | 0 |
| Year (annual) | 7,029 | 708 |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00393574. 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 Harrington's climate compare?
Harrington is warmer than 80 of the 100 places with their own NOAA record in South Dakota, and wetter than 44. Across the 7,247 U.S. stations with normals, its annual mean of 47.6°F is warmer than 30%.
In the Köppen classification computed from these normals, Harrington 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 Harrington 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.
- Parmelee, SD637 people · 16 mi NE
- Cody, NE172 people · 16 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 Harrington's climate
What is the coldest month at Harrington?
January, with a normal high of 35°F and a normal low of 12°F. The warmest is July (87°F by day, 60°F at night).
Does it snow at Harrington?
Yes: 47 inches in a normal year, falling on 21 days with 0.1 inch or more, the most in November (8.7 inches).
What is the rainiest month at Harrington?
June, with 3.99 in of precipitation in a normal year; the driest is January with 0.52 in.
What plant hardiness zone is Harrington in?
The USDA's 2023 map puts Harrington in zone 5a in ZIP code 57574, the nearest ZIP area. By the same method at the station, the coldest night of a typical year reaches −21°F (16 years, 1991-2020): zone 4b.
How late can frost come at Harrington?
In half of years the last 32°F night comes after May 11; in one year in ten it comes after May 24. Waiting until May 24 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
- Kilgore, NE22 miles from this station, 46.1°F a year
- Longvalley, SD24 miles from this station, 49.0°F a year
- Martin, SD24 miles from this station, 47.4°F a year
- Merriman, NE29 miles from this station, 47.6°F a year
- Compare two placesMonth by month, side by side
Download these normals (CSV) · JSON · How these figures are made