Merrimack County Climate
Merrimack County, New Hampshire
NOAA NCEI 1991-2020 Climate NormalsAvg Annual Temp
45.7°F
Annual Precip
46.8"
Annual Snowfall
73.7"
Extreme Heat Days
7
days >= 90°F/yr
Monthly Temperature
Precipitation Calendar
Growing Season & Gardening
5b
Minimum winter temperature range for plant survival
2,187
Favors cool-season crops
Seasonal Overview
National Comparison
7-Day Outlook
Forecast
Current Conditions
Air Quality
Safety
Weather Alerts
Climate Advisory: Merrimack County
Climate Verdict
Merrimack County has a cool, averaging 45.7°F annually, moderately wet with 46.8 inches of annual precipitation, rare extreme heat with only 6.62 days above 90°F annually, heavy winter snowfall averaging 73.7 inches per year. This climate profile shapes everything from energy costs to outdoor recreation opportunities.
Seasonal Breakdown
Winters are very cold — January averages 21.1°F. summers are pleasantly cool with July averaging 69.4°F. The 48°F seasonal variation provides noticeable but manageable change.
Outdoor & Gardening Guidance
Winter sports enthusiasts benefit from reliable snow cover for 3-4 months annually.
Regional Context
Merrimack County closely matches the New Hampshire statewide average temperature of 45.4°F.
Climate Profile
About Merrimack County Weather
Central New England's Balanced Climate
Merrimack County averages 45.7°F annually, falling on the cooler side of the national median. This region serves as a typical example of the Northeast's seasonal volatility.
Reflecting the State Average
The county's 45.7°F annual temperature almost perfectly mirrors the New Hampshire state average of 45.4°F. It acts as the climatic heart of the state.
Consistent With Regional Patterns
With 46.8 inches of annual precipitation, Merrimack is nearly identical to the state average. Its 73.7 inches of snow is also very close to the totals found in neighboring Belknap.
Standard Winters and Sunny Julys
Winters are cold with a 23.9°F average and over six feet of snow annually. July heats up to an average of 69.4°F, bringing about 7 days of 90-degree weather.
All-Season Home Preparation
Efficient HVAC systems are necessary to bridge the gap between 21.1°F Januarys and 69.4°F Julys. Good drainage is also helpful given the 46.8 inches of annual rainfall.
Frequently Asked Questions
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Data sources: NOAA National Centers for Environmental Information (NCEI), U.S. Climate Normals 1991-2020. Forecast and alert data from National Weather Service API. Air quality data from Open-Meteo.
Climate normals are 30-year averages of weather variables. Station data is aggregated to county level. Forecasts and alerts are fetched live and may change frequently. Data is informational only — not a substitute for official National Weather Service forecasts or emergency weather warnings.