30-year climate normals

Arapahoe County Climate and Weather Averages

Hottest month — July

89.9°

average daily high. The coldest month is December, averaging a low of 18.4°F.

Arapahoe County gets 14.48" of precipitation a year, and 43% of it falls in May, Jun, Jul.

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	44.6°	18.7°	0.38"
February	45.7°	19.7°	0.41"
March	55.7°	27.5°	0.86"
April	61.7°	33.9°	1.68"
May	71.2°	43.6°	2.16"
June	83.4°	53.0°	1.94"
July	89.9°	60.2°	2.14"
August	87.5°	58.3°	1.58"
September	79.6°	50.0°	1.35"
October	65.3°	37.0°	0.99"
November	52.9°	26.0°	0.64"
December	44.0°	18.4°	0.35"

Rainfall by month

Precipitation is spread fairly evenly through the year here, with 43% falling in the wettest three months (May, Jun, Jul).

January 0.38"

February 0.41"

March 0.86"

April 1.68"

May 2.16"

June 1.94"

July 2.14"

August 1.58"

September 1.35"

October 0.99"

November 0.64"

December 0.35"

Annual total 14.48"

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 850

Heating degree days How much heating the climate demands 5,862

Approximate annual cooling cost At 16.16¢/kWh, Colorado average $137

Approximate annual electric heating cost Lower where heating is gas rather than electric $332

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 Arapahoe County, where electricity is one line of eight.

Common questions

What is the weather like in Arapahoe County?

Arapahoe County averages a high of 89.9°F in July and a low of 18.4°F in December. Annual precipitation is 14.48 inches, with essentially no snow.

When is the rainy season in Arapahoe County?

The wettest stretch is May, Jun, Jul, which accounts for 43% of the year's precipitation. Precipitation is relatively evenly distributed across the year.

How hot does it get in Arapahoe County?

The average daily high in July, the hottest month, is 89.9°F. That drives 850 cooling degree days a year, which is what your air conditioning has to work against.

Does it snow in Arapahoe County?

Effectively no. Measurable snowfall is rare in Arapahoe County.

Sources

Temperature, precipitation and snowfall normals — NOAA National Centers for Environmental Information, 1991–2020 Monthly Climate Normals, station DENVER INTL AP, CO US (USW00003017), 21.7 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, Colorado residential average.
Wet-season share is the wettest three consecutive months as a percentage of annual precipitation, calculated from the monthly normals.