Pactola Dam, South Dakota climate: Climate normals at a NOAA weather station
Pactola Dam's normal year runs from 11°F January nights to 79°F July afternoons, with 21.5 inches of precipitation and 61 inches of snow a year. (NOAA 1991-2020 normals)
In metric: a yearly mean of 5.6°C, January lows of −11°C, July highs of 26°C, 547 mm of precipitation a year.
- NOAA stationPactola Dam
- Station IDUSC00396427
- Location44.06°N 103.48°W
- Elevation4,720 ft (1,439 m)
On October 23, the normal high in Pactola Dam is 53°F and the normal low 27°F, and the chance of measurable rain or snow is 21%.
Normals describe a typical year at the station, not a forecast. The National Weather Service forecast for Pactola Dam.
- Jan 36° 11°
- Feb 36° 11°
- Mar 44° 19°
- Apr 51° 26°
- May 60° 36°
- Jun 71° 45°
- Jul 79° 51°
- Aug 78° 49°
- Sep 69° 40°
- Oct 55° 29°
- Nov 45° 20°
- 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 Pactola Dam each month?
July is the warmest month, with normal highs of 79°F; January the coldest, with normal lows of 11°F. The most precipitation falls in May (4.26 in), the least in January (0.33 in).
| Month | High | Low | Mean | Precip. | Snow | Wet days | 90°F days | Freezing nights | Daylight |
|---|---|---|---|---|---|---|---|---|---|
| January | 36°F | 11°F | 23.6°F | 0.33 | 5.7 | 6 | <1 | 31 | 9 h 10 min |
| February | 36°F | 11°F | 23.7°F | 0.56 | 8.2 | 7 | <1 | 28 | 10 h 30 min |
| March | 44°F | 19°F | 31.3°F | 1.05 | 10.5 | 8 | <1 | 30 | 11 h 50 min |
| April | 51°F | 26°F | 38.3°F | 2.32 | 12.8 | 10 | <1 | 25 | 13 h 20 min |
| May | 60°F | 36°F | 48.1°F | 4.26 | 4.5 | 13 | <1 | 11 | 14 h 40 min |
| June | 71°F | 45°F | 57.9°F | 3.53 | 0.2 | 13 | 1 | 1 | 15 h 30 min |
| July | 79°F | 51°F | 64.8°F | 3.07 | 0.0 | 12 | 3 | <1 | 15 h 10 min |
| August | 78°F | 49°F | 63.3°F | 2.38 | 0.0 | 9 | 2 | <1 | 14 h |
| September | 69°F | 40°F | 54.4°F | 1.59 | 0.8 | 7 | 1 | 6 | 12 h 40 min |
| October | 55°F | 29°F | 42.4°F | 1.55 | 6.3 | 7 | <1 | 21 | 11 h 10 min |
| November | 45°F | 20°F | 32.5°F | 0.53 | 6.5 | 5 | <1 | 29 | 9 h 40 min |
| December | 37°F | 13°F | 24.7°F | 0.36 | 5.4 | 5 | <1 | 31 | 8 h 50 min |
| Year (annual) | 55°F | 29°F | 42.1°F | 21.53 | 60.9 | 103 | 6 | 212 |
The same normals in °C and millimetres
| Month | High | Low | Mean | Precip. | Snow |
|---|---|---|---|---|---|
| January | 2°C | −11°C | −4.7°C | 8 mm | 14 cm |
| February | 2°C | −12°C | −4.6°C | 14 mm | 21 cm |
| March | 7°C | −7°C | −0.4°C | 27 mm | 27 cm |
| April | 10°C | −3°C | 3.5°C | 59 mm | 33 cm |
| May | 16°C | 2°C | 8.9°C | 108 mm | 11 cm |
| June | 22°C | 7°C | 14.4°C | 90 mm | 1 cm |
| July | 26°C | 11°C | 18.2°C | 78 mm | 0 cm |
| August | 26°C | 9°C | 17.4°C | 60 mm | 0 cm |
| September | 21°C | 4°C | 12.4°C | 40 mm | 2 cm |
| October | 13°C | −1°C | 5.8°C | 39 mm | 16 cm |
| November | 7°C | −6°C | 0.3°C | 13 mm | 17 cm |
| December | 3°C | −11°C | −4.1°C | 9 mm | 14 cm |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00396427; 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 Pactola Dam?
Normal highs sit between 65°F and 85°F in 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 USC00396427.
When is the last frost at Pactola Dam?
In Pactola Dam, the last spring frost (32°F) comes after May 28 in half of years and after June 11 in one year in ten; the first autumn frost comes before September 18 in half of years and before September 4 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 281 year in 10 after June 11; 9 in 10 after May 16
- First autumn frost, half of years before
- September 181 year in 10 before September 4; 9 in 10 before October 1
NOAA puts the median frost-free season at 112 days, and the season without a hard freeze (28°F) at 136 days.
A hard freeze (28°F) comes after May 15 in half of springs and before September 29 in half of autumns.
The USDA's 2023 Plant Hardiness Zone Map puts Pactola Dam in zone 5a in ZIP code 57702, 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 5a: the coldest night of a typical year reaches −20°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 USC00396427; 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 Pactola Dam?
In a normal year in Pactola Dam, 6 days a year reach 90°F, 212 nights fall to 32°F or colder and 103 days bring measurable precipitation.
- Days at 90°F or more
- 6a normal year
- Days at 100°F or more
- fewer than 1a normal year
- Nights at 32°F or colder
- 212a normal year
- Days that stay below freezing
- 48high of 32°F or less
- Days with 0.01 inch of precipitation
- 103a normal year
- Days with 1 inch of snow or more
- 19a normal year
The highest temperature in this station's record (since 1955) is 101°F, on July 30, 2006; the lowest is −34°F, on January 19, 1963.
The wettest calendar year on that record is 2019, with 32.21 in; the snowiest season is 2019–20, with 101.6 inches.
Source: NOAA NCEI 1991-2020 annual normals, station USC00396427; records: ACIS (NOAA Regional Climate Centers), station USC00396427. Records use complete months only; a month missing more than three days is left out.
How sunny is it at Pactola Dam?
Over a year 78% of the sunlight that would reach the ground under clear skies gets through the clouds at Pactola Dam, 4.3 kWh per square metre a day. July is the sunniest month (86%) and April the cloudiest (71%).
| Month | Share of clear-sky sunshine | Sunshine, kWh/m² a day |
|---|---|---|
| January | 75% | 1.9 |
| February | 76% | 2.9 |
| March | 74% | 4.0 |
| April | 71% | 5.0 |
| May | 72% | 5.9 |
| June | 80% | 6.8 |
| July | 86% | 7.0 |
| August | 86% | 6.0 |
| September | 82% | 4.7 |
| October | 75% | 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 many heating and cooling degree days does Pactola Dam record?
A normal year at Pactola Dam brings 8,479 heating degree days, 58% more than the median U.S. place (5,373), and 153 cooling degree days, 83% fewer than the median (908). Nine months need 300 or more heating degree days, a monthly mean of about 55°F or colder. For gardens and crops, NOAA counts 1,448 growing degree days a year above 50°F.
| Month | Heating | Cooling |
|---|---|---|
| January | 1,283 | 0 |
| February | 1,156 | 0 |
| March | 1,045 | 0 |
| April | 801 | 0 |
| May | 525 | 1 |
| June | 231 | 18 |
| July | 81 | 73 |
| August | 103 | 50 |
| September | 327 | 10 |
| October | 701 | 0 |
| November | 977 | 0 |
| December | 1,249 | 0 |
| Year (annual) | 8,479 | 153 |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00396427. 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 Pactola Dam been warmer than normal?
2025 averaged 42.1°F, equal to the 1991-2020 normal of 42.1°F. 2 of the 5 complete years since 2021 ran warmer than the normal.
| Year | Mean | Against normal | Precip. | Snow |
|---|---|---|---|---|
| 2021 | 42.8°F | +0.7°F | 18.96 | 74.3 |
| 2022 | 41.2°F | −0.9°F | 12.41 | 32.7 |
| 2023 | 42.0°F | −0.1°F | 26.91 | 71.3 |
| 2024 | 43.5°F | +1.4°F | 14.89 | 27.5 |
| 2025 | 42.1°F | at normal | 24.74 | 35.3 |
Over 42 complete years from 1957 to 2025, the station's annual mean temperature rose at a fitted 3.1°F per century (+0.17°C per decade). A fitted rate summarizes the whole record; single years swing well above and below it.
Source: observed years: ACIS, station USC00396427; trend: NOAA GHCN-Monthly v4. A year counts only with all twelve months complete.
How does Pactola Dam's climate compare?
Pactola Dam is warmer than 1 of the 100 places with their own NOAA record in South Dakota, and wetter than 39. Across the 7,247 U.S. stations with normals, its annual mean of 42.1°F is warmer than 10%.
In the Köppen classification computed from these normals, Pactola Dam is Dwb: continental, dry-winter, 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.
Questions about Pactola Dam's climate
What is the coldest month at Pactola Dam?
January, with a normal high of 36°F and a normal low of 11°F. The warmest is July (79°F by day, 51°F at night).
Does it snow at Pactola Dam?
Yes: 61 inches in a normal year, falling on 38 days with 0.1 inch or more, the most in April (12.8 inches).
What is the rainiest month at Pactola Dam?
May, with 4.26 in of precipitation in a normal year; the driest is January with 0.33 in.
What plant hardiness zone is Pactola Dam in?
The USDA's 2023 map puts Pactola Dam in zone 5a in ZIP code 57702, the nearest ZIP area. By the same method at the station, the coldest night of a typical year reaches −20°F (29 years, 1991-2020): zone 5a.
How late can frost come at Pactola Dam?
In half of years the last 32°F night comes after May 28; in one year in ten it comes after June 11. Waiting until June 11 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
- Johnson Siding, SD3 miles from this station, 45.1°F a year
- Hill City, SD9 miles from this station, 43.9°F a year
- Mount Rushmore National Memorial, SD13 miles from this station, 45.7°F a year
- Rochford (2 mi WNW), SD14 miles from this station, 38.8°F a year
- Compare two placesMonth by month, side by side
Download these normals (CSV) · JSON · How these figures are made