Wyoming

Guernsey, Wyoming Climate

NOAA 1991-2020 normals for Guernsey 2NW, 2.5 km from Guernsey

The warmest month is July, with an average high of 89°F; the coldest is January, with an average low of 14°F. A normal year brings 15.1 in of precipitation and 27.5 in of snow.

Temperature through the year

The normal daily high and low and the record for every date at Guernsey (GUR), since 2012. The line marks today.

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

Normals for Sep 24

Normal high
74°F
Normal low
44°F
Record high
87°Fin 2014
Record low
40°Fin 2013
Daylight
12 h 03 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
January40°F14°F70°F (2015)-23°F (2017)0.66 in2.2 in30.61,1770
February41°F16°F69°F (2017)-16°F (2014)0.54 in6.3 in26.41,0250
March52°F25°F81°F (2017)-5°F (2014)0.95 in3.1 in21.88310
April59°F32°F85°F (2012)10°F (2013)1.75 in3.5 in12.35820
May69°F43°F92°F (2012)24°F (2013)2.85 in0.6 in2.530918
June81°F53°F104°F (2012)40°F (2014)2.08 in0.0 in0.053111
July89°F60°F103°F (2012)47°F (2014)1.73 in0.0 in0.03288
August88°F58°F99°F (2015)41°F (2015)1.20 in0.0 in0.012244
September78°F48°F97°F (2013)31°F (2014)1.20 in0.0 in0.613163
October63°F34°F88°F (2015)17°F (2017)1.29 in2.4 in11.55072
November50°F23°F76°F (2015)-13°F (2014)0.51 in3.2 in25.18590
December40°F15°F70°F (2014)-23°F (2016)0.34 in6.2 in29.71,1560
Year62°F35°F15.10 in27.5 in1616,645725

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.

15.1 in in a normal year, most in May.

Chance of a wet day

The chance of at least 0.01 inch of precipitation on each date at Guernsey, in percent, and of at least 0.1 inch of snowfall.0246810JanFebMarAprMayJunJulAugSepOctNovDec
  • Chance of a wet day
  • Chance of snowfall

Snow

NOAA 1991-2020 snowfall normals for Old Ft Laramie, 16.9 km away; Guernsey 2NW keeps no snowfall normals.

27.5 in of snow in a normal year.

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Guernsey 2NW. 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 May 7 and the first fall freeze around October 6, a growing season of about 152 days.

Median at 36°F
last May 18, first September 28
Median at 32°F
last May 7, first October 6
Median at 28°F
last April 28, first October 16

Frost dates, growing season and degree days

Humidity and comfort

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

Days with a mean dew point of 65°F or more are rare here in every month.

MonthDew pointHumidityDryComfortableHumidMuggyOppressiveMiserable
January17°F65%100%0%0%0%0%0%
February17°F62%100%0%0%0%0%0%
March22°F57%100%0%0%0%0%0%
April27°F55%100%0%0%0%0%0%
May36°F55%100%0%0%0%0%0%
June44°F50%98%2%0%0%0%0%
July49°F46%85%13%1%0%0%0%
August47°F46%91%9%0%0%0%0%
September38°F48%100%0%0%0%0%0%
October29°F56%100%0%0%0%0%0%
November21°F60%100%0%0%0%0%0%
December17°F66%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 September, with the sky 47 percent covered on average; the cloudiest is April, 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 January, averaging 13.4 mph at 10 meters (33 feet) above the ground.

Daylight and sunshine

The longest day is Jun 18, with 15 h 17 min of daylight; the shortest is Dec 17, with 9 h 05 min.

Hours of daylight at Guernsey 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 Platte 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 Platte County: 71.8°F (+2.9 °F against 1991-2020), the 6th warmest in 132 years on record.

August 2026 in Platte County: 2.40 in (+1.21 in against 1991-2020), the 2nd wettest in 132 years on record.

January to August 2026 in Platte County: 54.2°F (+4.8 °F against 1991-2020), the warmest in 132 years on record.

January to August 2026 in Platte County: 7.87 in (-3.16 in against 1991-2020), the 19th driest in 132 years on record.

Warmest August
73.1°F in 2020
Coolest August
62.6°F in 1927
Wettest August
4.46 in in 1930
Driest August
0.09 in in 2012

Every year since 1895

Each year's average temperature in Platte County against the 1991-2020 average, in °F, 1895 to 2025.-7.5-5-2.50+2.5+5+7.51900192019401960198020002020NOAA NCEI Climate at a Glance

Wyoming climate and rankings

Month pages

The weather in Guernsey 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 2012. 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 USC00484131 (Guernsey 2NW), public domain. Records: NOAA GHCN-Daily, station USC00484131, 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.