30-year climate normals

Imperial County Climate and Weather Averages

Hottest month — July

107.8°

average daily high. The coldest month is December, averaging a low of 41.2°F.

Imperial County gets 2.38" of precipitation a year, and 47% of it falls in Dec, Jan, Feb.

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	70.5°	41.5°	0.41"
February	73.7°	45.2°	0.38"
March	80.1°	50.6°	0.29"
April	86.3°	55.5°	0.08"
May	94.3°	62.1°	0.07"
June	103.5°	70.2°	0.00"
July	107.8°	78.4°	0.11"
August	107.7°	79.4°	0.15"
September	102.2°	72.2°	0.18"
October	90.4°	60.0°	0.19"
November	78.3°	48.4°	0.18"
December	68.7°	41.2°	0.34"

Rainfall by month

Imperial County has a distinct wet season. 47% of the year's precipitation arrives in Dec, Jan, Feb.

January 0.41"

February 0.38"

March 0.29"

April 0.08"

May 0.07"

June 0.00"

July 0.11"

August 0.15"

September 0.18"

October 0.19"

November 0.18"

December 0.34"

Annual total 2.38"

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 4,162

Heating degree days How much heating the climate demands 966

Approximate annual cooling cost At 33.25¢/kWh, California average $1,384

Approximate annual electric heating cost Lower where heating is gas rather than electric $112

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 Imperial County, where electricity is one line of eight.

Common questions

What is the weather like in Imperial County?

Imperial County averages a high of 107.8°F in July and a low of 41.2°F in December. Annual precipitation is 2.38 inches, with essentially no snow.

When is the rainy season in Imperial County?

The wettest stretch is Dec, Jan, Feb, which accounts for 47% 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 Imperial County?

The average daily high in July, the hottest month, is 107.8°F. That drives 4,162 cooling degree days a year, which is what your air conditioning has to work against.

Does it snow in Imperial County?

Effectively no. Measurable snowfall is rare in Imperial County.

Sources

Temperature, precipitation and snowfall normals — NOAA National Centers for Environmental Information, 1991–2020 Monthly Climate Normals, station IMPERIAL CO AP, CA US (USW00003144), 19.3 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, California residential average.
Wet-season share is the wettest three consecutive months as a percentage of annual precipitation, calculated from the monthly normals.