30-year climate normals

Big Horn County Climate and Weather Averages

Hottest month — July

90.0°

average daily high. The coldest month is January, averaging a low of 10.4°F.

Big Horn County gets 16.48" of precipitation a year, and 49% 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	38.1°	10.4°	0.39"
February	40.9°	11.9°	0.41"
March	51.4°	20.9°	0.73"
April	60.5°	29.2°	2.08"
May	70.7°	37.9°	3.85"
June	80.7°	48.1°	2.09"
July	90.0°	52.2°	1.67"
August	87.4°	49.3°	0.67"
September	77.6°	40.2°	1.41"
October	61.0°	29.1°	1.83"
November	47.2°	19.1°	0.81"
December	38.1°	11.2°	0.54"

Rainfall by month

Big Horn County has a distinct wet season. 49% of the year's precipitation arrives in Apr, May, Jun.

January 0.39"

February 0.41"

March 0.73"

April 2.08"

May 3.85"

June 2.09"

July 1.67"

August 0.67"

September 1.41"

October 1.83"

November 0.81"

December 0.54"

Annual total 16.48"

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 468

Heating degree days How much heating the climate demands 7,375

Approximate annual cooling cost At 14.67¢/kWh, Montana average $69

Approximate annual electric heating cost Lower where heating is gas rather than electric $379

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 90.0°F in July and a low of 10.4°F in January. Annual precipitation is 16.48 inches, with essentially no snow.

When is the rainy season in Big Horn County?

The wettest stretch is Apr, May, Jun, which accounts for 49% 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 90.0°F. That drives 468 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 WYOLA 1 SW, MT US (USC00249175), 20.5 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, Montana residential average.
Wet-season share is the wettest three consecutive months as a percentage of annual precipitation, calculated from the monthly normals.