30-year climate normals

Big Horn County Climate and Weather Averages

Hottest month — July

91.4°

average daily high. The coldest month is January, averaging a low of 6.0°F.

Big Horn County gets 5.55" of precipitation a year, and 53% of it falls in Apr, May, Jun.

Temperature through the year

Each bar spans the average daily low to the average daily high for that month.

Month	Avg high	Avg low	Precip
January	28.9°	6.0°	0.15"
February	35.5°	11.8°	0.12"
March	51.2°	24.6°	0.22"
April	60.0°	33.4°	0.53"
May	70.4°	43.6°	1.33"
June	81.4°	52.6°	1.08"
July	91.4°	58.3°	0.16"
August	88.8°	55.8°	0.23"
September	76.7°	45.1°	0.83"
October	59.9°	33.1°	0.60"
November	43.5°	18.9°	0.19"
December	30.8°	7.9°	0.11"

Rainfall by month

Big Horn County has a distinct wet season. 53% of the year's precipitation arrives in Apr, May, Jun.

January 0.15"

February 0.12"

March 0.22"

April 0.53"

May 1.33"

June 1.08"

July 0.16"

August 0.23"

September 0.83"

October 0.60"

November 0.19"

December 0.11"

Annual total 5.55"

What this climate costs you

Degree days measure how hard a building has to work to stay comfortable. They are the reason two identical houses have very different power bills, and they are the link between the weather here and what you pay every month.

Cooling degree days How much air conditioning the climate demands 743

Heating degree days How much heating the climate demands 7,546

Approximate annual cooling cost At 14.8¢/kWh, Wyoming average $110

Approximate annual electric heating cost Lower where heating is gas rather than electric $391

These are rough planning figures from degree days and the state electricity price, not a bill estimate. House size, insulation and fuel type move them a lot. See the full cost of owning a home in Big Horn County, where electricity is one line of eight.

Common questions

What is the weather like in Big Horn County?

Big Horn County averages a high of 91.4°F in July and a low of 6.0°F in January. Annual precipitation is 5.55 inches, with essentially no snow.

When is the rainy season in Big Horn County?

The wettest stretch is Apr, May, Jun, which accounts for 53% of the year's precipitation. That is a pronounced wet season rather than rain spread evenly through the year.

How hot does it get in Big Horn County?

The average daily high in July, the hottest month, is 91.4°F. That drives 743 cooling degree days a year, which is what your air conditioning has to work against.

Does it snow in Big Horn County?

Effectively no. Measurable snowfall is rare in Big Horn County.

Sources

Temperature, precipitation and snowfall normals — NOAA National Centers for Environmental Information, 1991–2020 Monthly Climate Normals, station GREYBULL S BIG HORN AP, WY US (USW00024048), 4.3 miles from the county centroid.
Heating and cooling degree days — NOAA, same station and period.
Electricity price — US Energy Information Administration, Electric Power Monthly Table 5.6.A, Wyoming residential average.
Wet-season share is the wettest three consecutive months as a percentage of annual precipitation, calculated from the monthly normals.