This weather has a price Keeping the median Lewis County home comfortable runs roughly $396 a year in heating and cooling alone. See where it lands in the monthly bill

30-year climate normals

Lewis County Climate and Weather Averages

Hottest month: August

80.7°

average daily high. The coldest month is December, averaging a low of 21.2°F.

Lewis County gets 19.96" of precipitation a year and 28.9" of snow, and 37% 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	Snow
January	35.3°	21.9°	1.77"	7.4"
February	39.9°	23.6°	1.43"	5.6"
March	46.9°	27.6°	2.02"	3.6"
April	53.7°	32.5°	2.38"	1.0"
May	62.4°	38.8°	2.70"	0.0"
June	68.4°	43.7°	2.21"	0.0"
July	79.8°	47.8°	0.87"	0.0"
August	80.7°	47.6°	0.78"	0.0"
September	71.3°	41.5°	0.95"	0.0"
October	56.5°	33.5°	1.53"	0.1"
November	42.4°	27.2°	1.77"	2.8"
December	33.9°	21.2°	1.55"	8.4"

Rainfall by month

Precipitation is spread fairly evenly through the year here, with 37% falling in the wettest three months (Apr, May, Jun).

January 1.77"

February 1.43"

March 2.02"

April 2.38"

May 2.70"

June 2.21"

July 0.87"

August 0.78"

September 0.95"

October 1.53"

November 1.77"

December 1.55"

Annual total 19.96"

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 148

Heating degree days How much heating the climate demands 7,448

Approximate annual cooling cost At 14.37¢/kWh, Idaho average $21

Approximate annual electric heating cost Lower where heating is gas rather than electric $375

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 Lewis County, where electricity is one line of eight.

Common questions

What is the weather like in Lewis County?

Lewis County averages a high of 80.7°F in August and a low of 21.2°F in December. Annual precipitation is 19.96 inches, including 28.9 inches of snow.

When is the rainy season in Lewis County?

The wettest stretch is Apr, May, Jun, which accounts for 37% of the year's precipitation. Precipitation is relatively evenly distributed across the year.

How hot does it get in Lewis County?

The average daily high in August, the hottest month, is 80.7°F. That drives 148 cooling degree days a year, which is what your air conditioning has to work against.

Does it snow in Lewis County?

Yes. Lewis County averages 28.9 inches of snow a year.

Sources

Temperature, precipitation and snowfall normals: NOAA National Centers for Environmental Information, 1991 to 2020 Monthly Climate Normals, station NEZPERCE, ID US (USC00106424), 8.6 miles from the county centroid.
Heating and cooling degree days: NOAA, same station and period.
Annual figures on this page are the sum of that station's twelve monthly normals. NOAA also publishes a separately-computed annual normal, which can differ from the monthly sum by a few percent; we use the monthly series because the month-by-month breakdown above has to come from it.
Electricity price: US Energy Information Administration, Electric Power Monthly Table 5.6.A, Idaho residential average.
Wet-season share is the wettest three consecutive months as a percentage of annual precipitation, calculated from the monthly normals.