Hillsborough County

Every recorded tornado

1. Injuries and deaths are for the tornado’s whole path, which may extend beyond the county. Deaths recorded within Hillsborough 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 (1).

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. Dec 11, 2008Ice Storm, Eastern Hillsborough$15.0 million
   National Weather Service narrative

   Half an inch of ice accumulated on exposed surfaces across eastern Hillsborough County. Numerous wires down in Merrimack and Manchester. Trees, wires, and utility poles downed in Pelham.

2. Dec 11, 2008Ice Storm, Western And Central Hillsborough$12.0 million
   National Weather Service narrative

   Numerous trees and wires were downed in Mason, Greenville, New Ispwich, Temple, Peterborough, and Milford.

3. Mar 5, 2001Heavy Snow, Hillsborough$5.0 million
   National Weather Service narrative

   A major winter storm impacted southwest New Hampshire with near blizzard conditions. The slow-moving storm, which tracked south of New England, dumped over two feet of snow across Cheshire and Hillsborough Counties and knocked out power to tens of thousands of customers. Businesses and schools were shut down for several days in some communities. After the storm, the weight of the heavy wet snow caused several roof collapses of homes and businesses.As much as 30 inches of snow fell in Jaffrey. Other snowfall totals reported include 29 inches in Swanzey, 27 inches in Westmoreland, 25 inches in Keene and Francestown, 24 inches in Pelham, Hudson and Nashua, 22 inches in Rindge, and 21…

4. Feb 25, 2010High Wind, Eastern Hillsborough$2.5 million
   National Weather Service narrative

   The Automated Surface Observing System at Manchester Airport (KMHT) recorded sustained wind speeds of 43 mph and gusts to 63 mph. The wind downed numerous trees and wires across Bedford. In addition, a scout camp near Manchester (Camp Carpenter) reported around 200 downed trees on its property. They also sustained damage to many of their buildings.

5. May 13, 2006Flood$2.0 million
   National Weather Service narrative

   Heavy rainfall, most of it falling over a 100 hour period, caused widespread flooding across much of southern New Hampshire, where small streams and main stem rivers rose out of their banks. Major flooding of a number of small streams and main stem rivers occurred in Hillsborough County. The Governor of New Hampshire declared a State of Emergency for a time during this event, and the President declared major disaster status for those affected. At some locations, this was the worst flooding recorded since the 1938 Hurricane and the great rain/snowmelt floods in March 1936.The focus of heavy rain shifted to southern New Hampshire late Friday night through Monday morning with…

6. Feb 25, 2010High Wind, Western And Central Hillsborough$1.5 million
   National Weather Service narrative

   Numerous trees and wires were downed throughout Wilton, Milford, Goffstown, and Amherst.

7. Apr 16, 2007Flood$1.5 million
   National Weather Service narrative

   Flooding closed part of Route 202 in Peterborough, Route 122 and South Merrimack Road in Hollis, and widespread urban flooding in Nashua and Manchester. A mudslide closed a portion of Route 101 in Wilton. Minor to moderate flooding was observed on the larger mainstem rivers. The Merrimack River at Nashua crested at 23.5 feet at 8 am on the 17th (flood stage is 18 feet), while at Goffs Falls the Merrimack crested at 16.8 feet at 1 pm on the 17th (flood stage is 11 feet). The Contoocook River at Peterborough crested at 7.2 feet at 1 pm on the 16th (flood stage is 5.5 feet. The Souhegan River at Merrimack crested at 12.7 feet at 545 am on the 17th (flood stage is 9 feet).

8. Jul 16, 2024Thunderstorm Wind$1.0 million
   National Weather Service narrative

   The NWS Storm survey team confirmed straight line wind damage in Milford, NH due to a microburst. The team observed 7 damaged homes....two destroyed vehicles and approximately 150 downed trees. No known injuries or fatalities occurred with this |storm.

9. Jul 18, 2021Flash Flood$1.0 million
   National Weather Service narrative

   Approximately $1 Million in road damages reported town wide in Peterborogh. Old Town Farm Rd and Old Jaffrey Rd received significant damage. Old Town Farm Road is a dead end and had 18 homes isolated by the road washouts.

10. Dec 7, 1996Heavy Snow, Hillsborough$1.0 million
    National Weather Service narrative

    A low pressure system centered over Georgia at 7 AM on December 7th moved rapidly northeast across North Carolina. The intensifying system then moved about parallel to the Mid-Atlantic coast with its center reaching Plymouth County in southeastern Massachusetts during the early morning hours of December 8th, before passing along the New Hampshire coast by late morning. This storm dropped from 7 to 15 inches of heavy, wet snow on the region, resulting in widespread damage to trees and power lines. At the height of the storm on Saturday evening, December 7th, the Public Service Company of New Hampshire reported 94,000 electric customers were without power statewide and 16…

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

103°FJul 22, 2011

All-time low

−20°FFeb 13, 1967

Warmest night

80°FJul 20, 2019

Coldest day

1°FJan 14, 2004

Wettest day

4.99 inSep 11, 1954

Snowiest day

16.6 inMar 13, 2018

Hottest year

2024mean 52.7°F

Coldest year

1954mean 47.6°F

Wettest year

195456.54 in

Driest year

201527.45 in

Station Manchester Airport (USW00014710), 229 ft elevation, 6.0 miles from the population centre. Daily records from 1948 to October 26, 2026; 95.8% 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 USW00014710.
• 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 October 30, 2026.