30-year climate normals

Merrimack County Climate and Weather Averages

Hottest month — July

80.2°

average daily high. The coldest month is January, averaging a low of 13.2°F.

Merrimack County gets 48.63" of precipitation a year, and 28% of it falls in Oct, Nov, Dec.

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	31.1°	13.2°	3.29"
February	34.4°	14.7°	3.20"
March	42.3°	22.3°	3.51"
April	55.0°	30.8°	4.04"
May	66.7°	41.1°	4.10"
June	74.9°	51.2°	4.52"
July	80.2°	56.6°	4.11"
August	78.6°	54.6°	4.41"
September	71.2°	46.2°	3.92"
October	58.4°	36.1°	5.11"
November	46.6°	28.9°	4.07"
December	36.1°	19.7°	4.35"

Rainfall by month

Precipitation is spread fairly evenly through the year here, with 28% falling in the wettest three months (Oct, Nov, Dec).

January 3.29"

February 3.20"

March 3.51"

April 4.04"

May 4.10"

June 4.52"

July 4.11"

August 4.41"

September 3.92"

October 5.11"

November 4.07"

December 4.35"

Annual total 48.63"

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 325

Heating degree days How much heating the climate demands 7,417

Approximate annual cooling cost At 27.33¢/kWh, New Hampshire average $89

Approximate annual electric heating cost Lower where heating is gas rather than electric $709

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 Merrimack County, where electricity is one line of eight.

Common questions

What is the weather like in Merrimack County?

Merrimack County averages a high of 80.2°F in July and a low of 13.2°F in January. Annual precipitation is 48.63 inches, with essentially no snow.

When is the rainy season in Merrimack County?

The wettest stretch is Oct, Nov, Dec, which accounts for 28% of the year's precipitation. Precipitation is relatively evenly distributed across the year.

How hot does it get in Merrimack County?

The average daily high in July, the hottest month, is 80.2°F. That drives 325 cooling degree days a year, which is what your air conditioning has to work against.

Does it snow in Merrimack County?

Effectively no. Measurable snowfall is rare in Merrimack County.

Sources

Temperature, precipitation and snowfall normals — NOAA National Centers for Environmental Information, 1991–2020 Monthly Climate Normals, station SALISBURY, NH US (USC00277833), 4.7 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, New Hampshire residential average.
Wet-season share is the wettest three consecutive months as a percentage of annual precipitation, calculated from the monthly normals.