Grafton County

Every recorded tornado

1. Injuries and deaths are for the tornado’s whole path, which may extend beyond the county. Deaths recorded within Grafton County: 0.
2. Weak tornadoes were under-recorded before Doppler radar coverage became national in the early 1990s, so earlier decades read low. Ratings use the Fujita scale before February 2007 and the Enhanced Fujita scale after.

Storm Prediction Center severe weather database, 1950 to 2025.

Every storm within 100 miles

1. Tropical storms and hurricanes (34 kt or more, still tropical) at closest approach. Post-tropical remnants with gale-force winds are listed but not counted. Direct: track within 50 miles; near: within 100 miles. Distance is measured to the county boundary for counties and to the city centre for cities, using positions interpolated hourly between HURDAT2 fixes.

National Hurricane Center HURDAT2, 1851 to 2025.

Smoke overhead

1. A smoke day is a date on which a smoke plume traced by NOAA Hazard Mapping System analysts from satellite imagery covered this place's point (the county's population centre or the city centre). Counts here are of medium or heavy smoke. Since 2018 analysts have often drawn light smoke as one area over most of the continent, so light-smoke counts are not comparable from year to year. The plumes show smoke anywhere in the air above, not air quality at the ground, and smoke hidden by cloud is missed.

NOAA Hazard Mapping System smoke analysis, 2011 to 2026, retrieved October 30, 2026.

Claims by ZIP code

This product uses the Federal Emergency Management Agency's OpenFEMA API, but is not endorsed by FEMA. The Federal Government or FEMA cannot vouch for the data or analyses derived from these data after the data have been retrieved from the Agency's website(s).

OpenFEMA NFIP Redacted Claims v3, refreshed August 4, 2026. NOAA Storm Events through 2026.

River crests

River gauges

1. Crests are the highest and the recent crests the National Weather Service lists for each river gauge in the county that has a flood stage, not every flood. Flood categories use each gauge's current flood stages; crests from before levees, dams or channel changes may not be comparable. Crests measured on an old datum are left out of the rankings.

NOAA National Water Prediction Service gauge records, retrieved October 30, 2026.

1. The Palmer Drought Severity Index is computed by NOAA each month from the county's average temperature and precipitation, relative to the county's own climate. Zero is normal; -3 or lower is severe drought and -4 or lower extreme drought. It describes the long-term balance of moisture, not water supply or crop losses.

NOAA NCEI nClimDiv county Palmer Drought Severity Index, 1895 to September 2026, issued October 6, 2026.

Every earthquake of magnitude 4 or more within 50 miles

1. Earthquakes of magnitude 2.5 or more in the USGS Comprehensive Catalog since 1900. Within 50 miles means the epicentre lies within 50 miles of the county boundary (or inside the county).
2. Small earthquakes were under-recorded before the modern seismic networks of the 1970s and are still missed in remote areas, so early decades read low. Magnitudes are as the catalogue reports them and mix scales (moment, local and body-wave).

USGS ANSS Comprehensive Earthquake Catalog, 1900 to present, retrieved October 30, 2026.

Mapped landslides

Mapped by NASA (3), USGS Conterminous (2).

Deadly landslides

1. Landslides mapped in the USGS compilation of landslide inventories across the United States (version 3.0, 2025), rated probable or better. The compilation joins inventories made by federal and state agencies for different purposes and areas, so the number mapped in a county reflects how closely it has been surveyed as much as how often its slopes fail. An area with few records may simply not have been mapped. Deaths are as recorded in the inventories; a slide listed in two inventories is counted once.

USGS Landslide Inventories across the United States, version 3.0, retrieved October 27, 2026.

More event types since 1996

Costliest events since 1996

1. Jul 2, 2013Flash Flood$6.5 million
   National Weather Service narrative

   Heavy rain from slow moving thunderstorms produced flash flooding in Lebanon.

2. Jul 1, 2017Flash Flood$6.0 million
   National Weather Service narrative

   Two to three inches of rain fell in a short period of time in Lyme causing stream flooding and road washouts.

3. Jul 1, 2017Flash Flood$4.0 million
   National Weather Service narrative

   Thunderstorms produced 2 to 5 inches of rain in Orford washing out portions of Route 25A and numerous roads along the Connecticut River.

4. Aug 28, 2011Flood$3.0 million
   National Weather Service narrative

   Heavy rain from Tropical Storm Irene caused serious flooding on the Pemigewasset River at Plymouth (flood stage 13.0 ft), which crested at 21.7 ft.

5. Aug 28, 2011Flash Flood$3.0 million
   National Weather Service narrative

   Heavy rain from Tropical Storm Irene caused serious flash flooding in Lincoln.

6. Aug 28, 2011Flood$3.0 million
   National Weather Service narrative

   Heavy rain from Tropical Storm Irene caused flooding on the Connecticut River at West Lebanon (flood stage 18.0 ft), which crested at 29.6 ft.

7. Jul 11, 2019Flash Flood$2.9 million
   National Weather Service narrative

   Slow moving thunderstorms produced 4 to 7 inches of rain which fell in less than 6 hours, causing serious flash flooding. Many roads were flooded and destroyed. Several homes were also flooded and damaged. Groton and Orange New Hampshire were the most seriously affected. In Groton the Cockermouth River rose almost 8 feet in just over an hour, flooding much of Sculptured Rocks Road. Towns seriously affected were Campton, Canaan, Dorchester, Enfield, Grafton, Groton, Hebron, Orange, and Rumney.

8. Jun 27, 1998Flash Flood$1.5 million
   National Weather Service narrative

   From 3 to possibly as much as 6 inches of rain fell in 12 hours causing the Baker River and its tributaries to rise very rapidly. Bridges were destroyed, vehicles were washed away, and some towns were completely isolated as all roads in and out of the towns were flooded. Roads and bridges in much of the area were washed out. A 46 year old man drowned while trying to clear debris from a culvert when he was sucked into the culvert which led to a cistern under a home. The man's father was injured trying to rescue his son. Towns hit hard by the flooding included Bridgewater, Rumney, Groton, Hebron, Wentworth, and Campton.

9. Jan 7, 1998Ice Storm, Northern Grafton$1.3 million
   National Weather Service narrative

   A severe ICE STORM hit sections of New Hampshire from January 7 through January 9. The hardest hit areas in northern and central New Hampshire were generally between about 1000 and 2000 ft above sea level. While many cities and towns at lower elevations received only rain, towns at higher elevations, such as New London, where the temperatures were slightly cooler had freezing rain. Ice accreted several inches thick on trees, power lines, and other exposed surfaces causing many people in those areas to lose electrical service. Statewide, the storm knocked out power to about 55,000 customers, an estimated 125,000 people. During the time without power, residents and those involved…

10. Jan 7, 1998Ice Storm, Southern Grafton$1.3 million
    National Weather Service narrative

    A severe ICE STORM hit sections of New Hampshire from January 7 through January 9. The hardest hit areas in northern and central New Hampshire were generally between about 1000 and 2000 ft above sea level. While many cities and towns at lower elevations received only rain, towns at higher elevations, such as New London, where the temperatures were slightly cooler had freezing rain. Ice accreted several inches thick on trees, power lines, and other exposed surfaces causing many people in those areas to lose electrical service. Statewide, the storm knocked out power to about 55,000 customers, an estimated 125,000 people. During the time without power, residents and those involved…

1. Storm Events records before 1996 cover only tornadoes, thunderstorm wind and hail. Damage figures are as reported by the National Weather Service at the time, not adjusted for inflation.

NOAA NCEI Storm Events Database, 1950 to 2026, issued October 26, 2026.

All-time high

100°FJun 24, 2025

All-time low

−30°FJan 11, 1968

Warmest night

75°FAug 11, 2021

Coldest day

−5°F2 times, most recently Jan 4, 1981

Wettest day

4.70 inSep 16, 1999

Snowiest day

25.6 inFeb 7, 1978

Hottest year

2023mean 49.7°F

Coldest year

2003mean 42.7°F

Wettest year

200651.02 in

Driest year

196323.45 in

Station Lebanon Municipal Airport (USW00094765), 554 ft elevation, 22.7 miles from the population centre. Daily records from 1962 to October 28, 2026; 94.4% of days in the last 30 years are complete. Records at a single station can differ from a city’s official threaded record, which may combine several stations.

NOAA NCEI Global Historical Climatology Network Daily.

This product uses the Federal Emergency Management Agency's OpenFEMA API, but is not endorsed by FEMA. The Federal Government or FEMA cannot vouch for the data or analyses derived from these data after the data have been retrieved from the Agency's website(s).

OpenFEMA Disaster Declarations Summaries, retrieved October 30, 2026. Statewide declarations are not listed.

Neighbouring counties

• Tornadoes NOAA Storm Prediction Center severe weather database, through 2025.
• Tropical cyclones NOAA National Hurricane Center HURDAT2 (Atlantic; Northeast and Central Pacific), through 2025.
• Wildfire USGS/USFS Monitoring Trends in Burn Severity, through 2026.
• Storm events NOAA NCEI Storm Events Database, through 2026.
• Flood insurance OpenFEMA NFIP Redacted Claims v3, refreshed August 4, 2026.
• Declarations OpenFEMA Disaster Declarations Summaries v2, retrieved October 30, 2026.
• Weather records NOAA NCEI Global Historical Climatology Network Daily, station USW00094765.
• River crests NOAA National Weather Service, National Water Prediction Service river gauges, retrieved October 30, 2026.
• Drought NOAA NCEI nClimDiv county Palmer Drought Severity Index, through September 2026.
• Smoke NOAA NESDIS Hazard Mapping System smoke analysis, retrieved October 30, 2026.
• Landslides USGS Landslide Inventories across the United States, version 3.0 (2025).
• Earthquakes USGS ANSS Comprehensive Earthquake Catalog (ComCat), retrieved October 30, 2026.

Joins, thresholds and known limits are set out in the methodology. Found an error? Report it. Page built November 1, 2026.