This weather has a price Keeping the median Grand Isle County home comfortable runs roughly $741 a year in heating and cooling alone. See where it lands in the monthly bill

30-year climate normals

Grand Isle County Climate and Weather Averages

Hottest month: July

80.7°

average daily high. The coldest month is January, averaging a low of 10.0°F.

Grand Isle County gets 30.89" of precipitation a year, and 36% of it falls in Jun, Jul, Aug.

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	28.2°	10.0°	1.41"
February	31.0°	11.0°	1.22"
March	40.0°	20.5°	1.33"
April	54.0°	33.0°	2.55"
May	67.7°	44.4°	2.88"
June	75.4°	53.4°	4.07"
July	80.7°	59.1°	3.61"
August	78.9°	56.5°	3.58"
September	70.7°	48.7°	3.11"
October	57.6°	38.4°	3.04"
November	45.7°	28.8°	2.33"
December	34.1°	18.6°	1.76"

Rainfall by month

Precipitation is spread fairly evenly through the year here, with 36% falling in the wettest three months (Jun, Jul, Aug).

January 1.41"

February 1.22"

March 1.33"

April 2.55"

May 2.88"

June 4.07"

July 3.61"

August 3.58"

September 3.11"

October 3.04"

November 2.33"

December 1.76"

Annual total 30.89"

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 392

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

Approximate annual cooling cost At 24.44¢/kWh, Vermont average $96

Approximate annual electric heating cost Lower where heating is gas rather than electric $645

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 Grand Isle County, where electricity is one line of eight.

Common questions

What is the weather like in Grand Isle County?

Grand Isle County averages a high of 80.7°F in July and a low of 10.0°F in January. Annual precipitation is 30.89 inches, with essentially no snow.

When is the rainy season in Grand Isle County?

The wettest stretch is Jun, Jul, Aug, which accounts for 36% of the year's precipitation. Precipitation is relatively evenly distributed across the year.

How hot does it get in Grand Isle County?

The average daily high in July, the hottest month, is 80.7°F. That drives 392 cooling degree days a year, which is what your air conditioning has to work against.

Does it snow in Grand Isle County?

The weather station used for Grand Isle County, PLATTSBURGH INTL AP, NY US, reports temperature and precipitation but not snowfall, so there is no snow normal to quote here. Precipitation that falls as snow is still counted in the 30.89 inches above, measured as melted water.

Sources

Temperature, precipitation and snowfall normals: NOAA National Centers for Environmental Information, 1991 to 2020 Monthly Climate Normals, station PLATTSBURGH INTL AP, NY US (USW00064776), 13.3 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, Vermont residential average.
Wet-season share is the wettest three consecutive months as a percentage of annual precipitation, calculated from the monthly normals.