30-year climate normals

Ontario County Climate and Weather Averages

Hottest month — July

81.4°

average daily high. The coldest month is January, averaging a low of 17.8°F.

Ontario County gets 35.19" of precipitation a year, and 31% 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	33.0°	17.8°	1.92"
February	34.6°	18.4°	1.77"
March	42.2°	24.9°	2.65"
April	55.2°	35.3°	3.21"
May	68.2°	46.8°	3.13"
June	76.9°	56.9°	3.58"
July	81.4°	62.0°	4.06"
August	80.2°	60.6°	3.31"
September	73.5°	53.8°	3.12"
October	60.8°	43.0°	3.46"
November	48.7°	33.4°	2.59"
December	38.1°	24.6°	2.39"

Rainfall by month

Precipitation is spread fairly evenly through the year here, with 31% falling in the wettest three months (Jun, Jul, Aug).

January 1.92"

February 1.77"

March 2.65"

April 3.21"

May 3.13"

June 3.58"

July 4.06"

August 3.31"

September 3.12"

October 3.46"

November 2.59"

December 2.39"

Annual total 35.19"

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 632

Heating degree days How much heating the climate demands 6,513

Approximate annual cooling cost At 29.93¢/kWh, New York average $189

Approximate annual electric heating cost Lower where heating is gas rather than electric $682

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 Ontario County, where electricity is one line of eight.

Common questions

What is the weather like in Ontario County?

Ontario County averages a high of 81.4°F in July and a low of 17.8°F in January. Annual precipitation is 35.19 inches, with essentially no snow.

When is the rainy season in Ontario County?

The wettest stretch is Jun, Jul, Aug, which accounts for 31% of the year's precipitation. Precipitation is relatively evenly distributed across the year.

How hot does it get in Ontario County?

The average daily high in July, the hottest month, is 81.4°F. That drives 632 cooling degree days a year, which is what your air conditioning has to work against.

Does it snow in Ontario County?

Effectively no. Measurable snowfall is rare in Ontario County.

Sources

Temperature, precipitation and snowfall normals — NOAA National Centers for Environmental Information, 1991–2020 Monthly Climate Normals, station CANANDAIGUA 3 S, NY US (USC00301152), 1.4 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, New York residential average.
Wet-season share is the wettest three consecutive months as a percentage of annual precipitation, calculated from the monthly normals.