30-year climate normals

Nassau County Climate and Weather Averages

Hottest month — July

91.9°

average daily high. The coldest month is January, averaging a low of 42.9°F.

Nassau County gets 53.4" of precipitation a year, and 40% 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	65.5°	42.9°	3.28"
February	68.9°	46.1°	2.86"
March	74.3°	50.6°	3.29"
April	79.8°	56.4°	2.93"
May	85.9°	63.9°	3.42"
June	89.9°	70.7°	7.60"
July	91.9°	73.2°	6.77"
August	90.8°	73.4°	6.88"
September	87.2°	70.5°	7.56"
October	80.9°	61.5°	4.03"
November	73.2°	51.3°	2.00"
December	67.5°	45.8°	2.78"

Rainfall by month

Precipitation is spread fairly evenly through the year here, with 40% falling in the wettest three months (Jun, Jul, Aug).

January 3.28"

February 2.86"

March 3.29"

April 2.93"

May 3.42"

June 7.60"

July 6.77"

August 6.88"

September 7.56"

October 4.03"

November 2.00"

December 2.78"

Annual total 53.4"

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 2,803

Heating degree days How much heating the climate demands 1,228

Approximate annual cooling cost At 15.17¢/kWh, Florida average $425

Approximate annual electric heating cost Lower where heating is gas rather than electric $65

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 Nassau County, where electricity is one line of eight.

Common questions

What is the weather like in Nassau County?

Nassau County averages a high of 91.9°F in July and a low of 42.9°F in January. Annual precipitation is 53.4 inches, with essentially no snow.

When is the rainy season in Nassau County?

The wettest stretch is Jun, Jul, Aug, which accounts for 40% of the year's precipitation. Precipitation is relatively evenly distributed across the year.

How hot does it get in Nassau County?

The average daily high in July, the hottest month, is 91.9°F. That drives 2,803 cooling degree days a year, which is what your air conditioning has to work against.

Does it snow in Nassau County?

Effectively no. Measurable snowfall is rare in Nassau County.

Sources

Temperature, precipitation and snowfall normals — NOAA National Centers for Environmental Information, 1991–2020 Monthly Climate Normals, station JACKSONVILLE, FL US (USW00013889), 9.2 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, Florida residential average.
Wet-season share is the wettest three consecutive months as a percentage of annual precipitation, calculated from the monthly normals.