New Hampshire
Mount Washington holds the world wind speed record outside of tornadoes. The White Mountains create their own weather. The 2005 floods devastated river communities. And ice storms knock out power to a state where many homes heat with oil furnaces that need electricity to run.
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Know your region
Franconia, North Conway, Berlin, Colebrook, the Presidential Range. Mount Washington recorded a 231 mph wind gust. Heavy snow, avalanche risk, and extreme cold define winter. Flash floods in steep notches and ravines develop during summer storms.
Primary hazards: winter storms, flash flooding, extreme cold, avalanche
Concord, Laconia, Keene, Claremont, the Connecticut and Merrimack rivers. The 2005 floods caused historic damage along both river systems. Dam failure risk exists along some tributaries. Ice storms coat power lines and bring down trees.
Primary hazards: flooding, ice storms, severe storms, winter storms
Manchester, Nashua, Portsmouth, the Seacoast. The most populated region faces nor'easters, severe thunderstorms, and the occasional tropical remnant. Coastal flooding threatens Portsmouth and Hampton Beach. Aging infrastructure amplifies storm impacts.
Primary hazards: nor'easters, coastal flooding, severe storms, ice storms
Your hazard profile
Each links to a full guide with during-event protocol, recovery steps, and resources specific to NH.
The 2008 ice storm left 400,000 without power. Northern New Hampshire receives over 100 inches of snow annually. Mount Washington's summit conditions are among the harshest on Earth. Rural communities can be isolated for days.
Read the winter storms and ice guide →
The 2005 floods caused historic damage along the Merrimack and Connecticut rivers. Flash flooding in steep White Mountain terrain develops rapidly. Dam failure risk exists along some rivers.
Read the flooding guide →
Summer storms bring damaging winds, hail, and dangerous lightning. Mountains enhance storm development. Microbursts topple trees and cause power outages across forested areas.
Read the severe thunderstorms guide →
Dry spring conditions before green-up create fire risk in New Hampshire's forests. The wildland-urban interface in lake region communities is a growing concern.
Read the wildfire guide →
The 1940 Ossipee earthquake (M5.5) was felt across New England. Small earthquakes occur periodically. The region's hard bedrock transmits seismic waves efficiently over long distances.
Read the earthquakes guide →
New Hampshire resources
New Hampshire Homeland Security and Emergency Management. Coordinates disaster response and manages the state's emergency alert system.
Covers most of New Hampshire. Winter storm warnings, flood advisories, and severe weather alerts.
Summit weather observations, higher summit forecasts, and educational programs about extreme mountain weather.
Statewide referral service. Energy assistance, fuel assistance, disaster recovery, and housing resources.
October 2005
In October 2005, heavy rain from a stalled storm system dropped 7 to 11 inches of rain across New Hampshire in 48 hours. The Merrimack, Contoocook, Suncook, and Pemigewasset rivers flooded to levels not seen in decades. Roads washed out. Bridges failed. The Suncook River actually changed course, abandoning its old channel and cutting a new one through a neighborhood in Epsom.
A river changing its channel is the kind of thing that happens over geological time. In 2005, it happened in an afternoon. The rain fell on saturated ground after a wet autumn. The terrain did the rest.
For New Hampshire households in river valleys, the lesson is terrain. Steep slopes and narrow valleys concentrate water. If your property is near a river or brook, know your flood history, know your evacuation route, and understand that "this has never flooded" is a statement about the past, not a guarantee about the future.