Gregory, South Dakota climate: Normal weather by month, frost dates and records
Gregory's normal year runs from 10°F January nights to 87°F July afternoons, with 26.7 inches of precipitation and 45 inches of snow a year. (NOAA 1991-2020 normals)
In metric: a yearly mean of 8.5°C, January lows of −12°C, July highs of 30°C, 677 mm of precipitation a year.
- NOAA stationGregory
- Station IDUSC00393452
- Location43.24°N 99.43°W
- Elevation2,160 ft (658 m)
- Population1,270
On October 22, the normal high in Gregory is 58°F and the normal low 33°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 Gregory.
- Jan 32° 10°
- Feb 36° 13°
- Mar 47° 23°
- Apr 58° 33°
- May 69° 45°
- Jun 80° 56°
- Jul 87° 62°
- Aug 85° 59°
- Sep 77° 50°
- Oct 62° 36°
- Nov 47° 23°
- Dec 35° 14°
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 Gregory each month?
July is the warmest month, with normal highs of 87°F; January the coldest, with normal lows of 10°F. The most precipitation falls in June (4.18 in), the least in January (0.55 in).
| Month | High | Low | Mean | Precip. | Snow | Wet days | 90°F days | Freezing nights | Daylight |
|---|---|---|---|---|---|---|---|---|---|
| January | 32°F | 10°F | 20.9°F | 0.55 | 6.8 | 3 | <1 | 30 | 9 h 20 min |
| February | 36°F | 13°F | 24.5°F | 0.75 | 8.5 | 4 | <1 | 27 | 10 h 30 min |
| March | 47°F | 23°F | 34.7°F | 1.34 | 5.3 | 5 | <1 | 25 | 11 h 50 min |
| April | 58°F | 33°F | 45.4°F | 3.12 | 5.4 | 8 | <1 | 14 | 13 h 20 min |
| May | 69°F | 45°F | 56.9°F | 4.13 | 0.0 | 10 | 1 | 2 | 14 h 40 min |
| June | 80°F | 56°F | 67.8°F | 4.18 | 0.0 | 10 | 4 | <1 | 15 h 20 min |
| July | 87°F | 62°F | 74.2°F | 2.99 | 0.0 | 7 | 12 | <1 | 15 h 10 min |
| August | 85°F | 59°F | 72.0°F | 3.14 | 0.0 | 7 | 9 | <1 | 14 h |
| September | 77°F | 50°F | 63.1°F | 2.41 | 0.0 | 6 | 4 | 1 | 12 h 30 min |
| October | 62°F | 36°F | 48.7°F | 2.36 | 1.7 | 6 | <1 | 11 | 11 h 10 min |
| November | 47°F | 23°F | 34.9°F | 0.95 | 6.9 | 4 | <1 | 25 | 9 h 50 min |
| December | 35°F | 14°F | 24.2°F | 0.74 | 10.4 | 4 | <1 | 30 | 9 h |
| Year (annual) | 59°F | 35°F | 47.3°F | 26.66 | 45.0 | 77 | 29 | 165 |
The same normals in °C and millimetres
| Month | High | Low | Mean | Precip. | Snow |
|---|---|---|---|---|---|
| January | 0°C | −12°C | −6.2°C | 14 mm | 17 cm |
| February | 2°C | −10°C | −4.2°C | 19 mm | 22 cm |
| March | 8°C | −5°C | 1.5°C | 34 mm | 13 cm |
| April | 14°C | 1°C | 7.4°C | 79 mm | 14 cm |
| May | 20°C | 7°C | 13.8°C | 105 mm | 0 cm |
| June | 26°C | 13°C | 19.9°C | 106 mm | 0 cm |
| July | 30°C | 17°C | 23.4°C | 76 mm | 0 cm |
| August | 29°C | 15°C | 22.2°C | 80 mm | 0 cm |
| September | 25°C | 10°C | 17.3°C | 61 mm | 0 cm |
| October | 16°C | 2°C | 9.3°C | 60 mm | 4 cm |
| November | 8°C | −5°C | 1.6°C | 24 mm | 18 cm |
| December | 1°C | −10°C | −4.3°C | 19 mm | 26 cm |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00393452; 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 Gregory?
Normal highs sit between 65°F and 85°F in May, June, August and September. Of those, September has the fewest days with rain (6).
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 USC00393452.
When is the last frost in Gregory?
In Gregory, the last spring frost (32°F) comes after May 6 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 21 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 20; 9 in 10 after April 23
- First autumn frost, half of years before
- October 31 year in 10 before September 21; 9 in 10 before October 17
NOAA puts the median frost-free season at 149 days, and the season without a hard freeze (28°F) at 168 days.
A hard freeze (28°F) comes after April 26 in half of springs and before October 13 in half of autumns.
The USDA's 2023 Plant Hardiness Zone Map puts Gregory in zone 5a in ZIP code 57529, the nearest ZIP area. By the map's own method, the average of each year's coldest night over 1991-2020, Gregory's NOAA station is in zone 5a: the coldest night of a typical year reaches −18°F (29 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 USC00393452; 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 Gregory?
In a normal year in Gregory, 29 days a year reach 90°F (3 of them 100°F or more), 165 nights fall to 32°F or colder and 77 days bring measurable precipitation.
- Days at 90°F or more
- 29a normal year
- Days at 100°F or more
- 3a normal year
- Nights at 32°F or colder
- 165a normal year
- Days that stay below freezing
- 53high of 32°F or less
- Days with 0.01 inch of precipitation
- 77a normal year
- Days with 1 inch of snow or more
- 13a normal year
The highest temperature in this station's record (since 1906) is 114°F, on July 16, 1936; the lowest is −36°F, on December 21, 1983.
The wettest calendar year on that record is 2019, with 41.60 in; the snowiest season is 1969–70, with 78.0 inches.
Source: NOAA NCEI 1991-2020 annual normals, station USC00393452; records: ACIS (NOAA Regional Climate Centers), station USC00393452. Records use complete months only; a month missing more than three days is left out.
How sunny is Gregory?
Over a year 78% of the sunlight that would reach the ground under clear skies gets through the clouds in the area around Gregory, 4.2 kWh per square metre a day. July is the sunniest month (86%) and April the cloudiest (72%).
| Month | Share of clear-sky sunshine | Sunshine, kWh/m² a day |
|---|---|---|
| January | 75% | 2.0 |
| February | 76% | 3.0 |
| March | 72% | 3.9 |
| April | 72% | 5.0 |
| May | 74% | 5.9 |
| June | 80% | 6.7 |
| July | 86% | 6.9 |
| August | 84% | 5.8 |
| September | 82% | 4.6 |
| October | 76% | 3.1 |
| November | 75% | 2.1 |
| December | 72% | 1.6 |
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 Gregory need?
A normal year in Gregory brings 7,208 heating degree days, 34% more than the median U.S. place (5,373), and 779 cooling degree days, 14% 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 2,833 growing degree days a year above 50°F.
| Month | Heating | Cooling |
|---|---|---|
| January | 1,369 | 0 |
| February | 1,134 | 0 |
| March | 941 | 0 |
| April | 588 | 2 |
| May | 279 | 28 |
| June | 53 | 135 |
| July | 7 | 290 |
| August | 17 | 233 |
| September | 140 | 84 |
| October | 512 | 6 |
| November | 903 | 0 |
| December | 1,266 | 0 |
| Year (annual) | 7,208 | 779 |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00393452. 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 Gregory been warmer than normal lately?
2025 averaged 48.6°F, 1.3°F above the 1991-2020 normal of 47.3°F. 4 of the 5 complete years since 2021 ran warmer than the normal.
| Year | Mean | Against normal | Precip. | Snow |
|---|---|---|---|---|
| 2021 | 49.1°F | +1.8°F | 21.15 | 42.3 |
| 2022 | 47.1°F | −0.2°F | 18.98 | 31.9 |
| 2023 | 48.2°F | +0.9°F | 31.20 | 69.7 |
| 2024 | 49.6°F | +2.3°F | 21.96 | 34.6 |
| 2025 | 48.6°F | +1.3°F | 23.04 | 28.4 |
Over 83 complete years from 1932 to 2025, the station's annual mean temperature rose at a fitted 1.0°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 USC00393452; trend: NOAA GHCN-Monthly v4. A year counts only with all twelve months complete.
How does Gregory's climate compare?
Gregory is warmer than 70 of the other 99 places with their own NOAA record in South Dakota, and wetter than 82. Across the 7,247 U.S. stations with normals, its annual mean of 47.3°F is warmer than 29%.
In the Köppen classification computed from these normals, Gregory 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 Gregory 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.
- Burke, SD590 people · 8 mi SE
- Dallas, SD86 people · 4 mi W
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 Gregory's climate
What is the coldest month in Gregory?
January, with a normal high of 32°F and a normal low of 10°F. The warmest is July (87°F by day, 62°F at night).
Does it snow in Gregory?
Yes: 45 inches in a normal year, falling on 16 days with 0.1 inch or more, the most in December (10.4 inches).
What is the rainiest month in Gregory?
June, with 4.18 in of precipitation in a normal year; the driest is January with 0.55 in.
What plant hardiness zone is Gregory in?
The USDA's 2023 map puts Gregory in zone 5a in ZIP code 57529, the nearest ZIP area. By the same method at Gregory's NOAA station, the coldest night of a typical year reaches −18°F (29 years, 1991-2020): zone 5a.
How late can frost come in Gregory?
In half of years the last 32°F night comes after May 6; 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
- Winner, SD23 miles from this station, 50.2°F a year
- Academy (2 mi NE), SD25 miles from this station, 47.7°F a year
- Bonesteel, SD27 miles from this station, 47.6°F a year
- Springview, NE32 miles from this station, 47.1°F a year
- Compare two placesMonth by month, side by side
Download these normals (CSV) · JSON · How these figures are made