South Dakota

Platte, South Dakota Climate

NOAA 1991-2020 normals for Academy 2NE, 21 km from Platte

The warmest month is July, with an average high of 87°F; the coldest is January, with an average low of 11°F. A normal year brings 24.0 in of precipitation and 41.5 in of snow.

Temperature through the year

The normal daily high and low and the record for every date at Wagner (AGZ), since 1916. The line marks today.

Normal daily high and low temperature at Platte through the year, in °F, with the record for each date.-50050100150JanFebMarAprMayJunJulAugSepOctNovDec
  • Normal low
  • Normal high
  • Record high
  • Record low

Normals for Sep 25

Normal high
73°F
Normal low
47°F
Record high
94°Fin 1938
Record low
27°Fin 1926
Chance of a wet day
24%
Daylight
12 h 01 min

Month by month

Averages for 1991-2020. Wet days have at least 0.01 inch of precipitation. Freeze nights have a low of 32°F or colder; degree days are on a 65°F base. Each month links to its own page.

MonthAvg highAvg lowRecord highRecord lowPrecipitationWet daysSnowfallFreeze nightsHeating DDCooling DD
January30°F11°F70°F (1981)-32°F (1924)0.51 in5.45.8 in30.71,3860
February35°F14°F74°F (1981)-35°F (1933)0.58 in5.67.7 in27.21,1380
March46°F24°F95°F (1943)-21°F (1960)1.12 in6.56.5 in25.59310
April58°F35°F100°F (1962)-1°F (1936)2.68 in9.36.8 in14.05643
May69°F47°F107°F (1934)20°F (1961)3.53 in11.20.0 in2.025635
June80°F58°F112°F (1937)32°F (1956)3.89 in11.40.0 in0.044158
July87°F63°F115°F (1936)41°F (1971)3.03 in8.60.0 in0.07311
August85°F60°F113°F (1930)35°F (1950)2.99 in8.20.0 in0.015247
September77°F51°F106°F (1959)20°F (1918)2.54 in7.00.0 in0.813298
October62°F37°F99°F (1947)0°F (1991)1.82 in7.21.1 in11.14938
November46°F25°F82°F (1964)-17°F (1959)0.80 in4.95.4 in25.08850
December33°F15°F75°F (1939)-39°F (1917)0.50 in5.58.2 in30.61,2680
Year59°F37°F23.99 in9141.5 in1677,117859

Precipitation

Rain and melted snow together. The chance of a wet day is the share of days with at least 0.01 inch of precipitation.

24.0 in in a normal year, most in June.

Chance of a wet day

The chance of at least 0.01 inch of precipitation on each date at Platte, in percent, and of at least 0.1 inch of snowfall.010203040JanFebMarAprMayJunJulAugSepOctNovDec
  • Chance of a wet day
  • Chance of snowfall

Snow

NOAA 1991-2020 snowfall normals for Academy 2NE.

41.5 in of snow in a normal year.

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Academy 2NE. A median date has an even chance of a later freeze in spring, or an earlier one in fall.

The last spring freeze typically comes around April 30 and the first fall freeze around October 8, a growing season of about 159 days.

Median at 36°F
last May 9, first September 29
Median at 32°F
last April 30, first October 8
Median at 28°F
last April 19, first October 18

Frost dates, growing season and degree days

Humidity and comfort

NASA POWER reanalysis, 1991-2020, for the grid cell around Platte.

The muggiest month is July, when 23 percent of days are muggy or worse, with a mean dew point of 65°F or more.

MonthDew pointHumidityDryComfortableHumidMuggyOppressiveMiserable
January15°F79%100%0%0%0%0%0%
February17°F74%100%0%0%0%0%0%
March25°F68%100%0%0%0%0%0%
April34°F64%99%1%0%0%0%0%
May45°F63%86%9%5%0%0%0%
June56°F64%45%23%18%13%2%0%
July59°F59%28%24%25%18%5%0%
August58°F60%35%27%23%13%2%0%
September48°F59%76%15%8%2%0%0%
October36°F64%98%1%0%0%0%0%
November26°F72%100%0%0%0%0%0%
December18°F80%100%0%0%0%0%0%

Comfort is judged by the day's mean dew point: dry below 55°F, comfortable to 60°F, humid to 65°F, muggy to 70°F, oppressive to 75°F, miserable above.

Clouds

Average share of the sky covered, from satellite (CERES and GEWEX SRB) by way of NASA POWER, 1991-2020.

The clearest month is July, with the sky 47 percent covered on average; the cloudiest is March, at 66 percent.

Wind

The mean wind speed over the whole day, from the MERRA-2 reanalysis by way of NASA POWER. Gusts run well above it.

The windiest month is April, averaging 12.5 mph at 10 meters (33 feet) above the ground.

Daylight and sunshine

The longest day is Jun 17, with 15 h 25 min of daylight; the shortest is Dec 20, with 8 h 57 min.

Hours of daylight at Platte through the year.0510152025JanFebMarAprMayJunJulAugSepOctNovDec
  • Day length

Solar energy

Average daily sunshine reaching the ground on a flat surface, in kilowatt-hours per square meter, clouds included.

Sunrise and sunset calendar

How Charles Mix County is running

NOAA NCEI Climate at a Glance, from the nClimGrid analysis of every station, updated early each month. A rank of 1 is the highest or lowest of all years since 1895.

August 2026 in Charles Mix County: 74.1°F (+1.4 °F against 1991-2020), the 44th warmest in 132 years on record.

August 2026 in Charles Mix County: 1.88 in (-1.22 in against 1991-2020), the 43rd driest in 132 years on record.

January to August 2026 in Charles Mix County: 54.0°F (+3.3 °F against 1991-2020), the 6th warmest in 132 years on record.

January to August 2026 in Charles Mix County: 13.33 in (-5.60 in against 1991-2020), the 13th driest in 132 years on record.

Warmest August
80.2°F in 1937
Coolest August
65.8°F in 1915
Wettest August
7.41 in in 1944
Driest August
0.55 in in 1983

Every year since 1895

Each year's average temperature in Charles Mix County against the 1991-2020 average, in °F, 1895 to 2025.-6-4-20+2+4+61900192019401960198020002020NOAA NCEI Climate at a Glance

South Dakota climate and rankings

Month pages

The weather in Platte in each month, day by day.

What this means

A normal is the average of the thirty years 1991 to 2020, the period the World Meteorological Organization and NOAA use for comparison. It is an average, not a forecast: most days depart from it, and some by a long way.

A record is the highest or lowest value on the date in every year the station has reported, back to 1916. It rests on one station, so a neighbor a few miles away can hold different ones.

Cloud, humidity, wind and sunshine come from a reanalysis: a weather model run over the past with every observation fed in, averaged over a grid cell about 50 km across. It is consistent everywhere on Earth; it smooths local detail such as a lake shore or a valley.

More for this place

Nearby

Sources

Normals: NOAA NCEI U.S. Climate Normals, 1991-2020, station USC00390043 (Academy 2NE), public domain. Records: NOAA GHCN-Daily, station USC00398767, every year on file, quality-flagged values removed. Cloud, humidity, wind and sunshine: NASA POWER (MERRA-2, CERES and GEWEX SRB), 1991-2020. The data was obtained from the National Aeronautics and Space Administration (NASA) Langley Research Center's Prediction Of Worldwide Energy Resources (POWER) project funded through the NASA Earth Science Division: POWER Daily API v2, accessed 2026-09-24. Sun and moon: computed with the NOAA solar equations and Meeus. Rankings: NOAA NCEI Climate at a Glance, public domain.