NHC HURDAT2 · SPC Tornado Database
Hurricanes and Tornadoes That Hit Thornton, NH
Every tropical system within 75 miles since 1851 and every tornado within 25 miles since 1950.
Data: NOAA NHC HURDAT2 and NOAA SPC tornado and hail reports, through 2025 · Updated
28 tropical systems have passed within 75 miles of Thornton, New Hampshire since 1851, 2 of them at hurricane strength; the most recent was Isaias in 2020. Since 1950, 17 tornadoes have touched down within 25 miles, 1 of them rated EF3 or stronger.
- Hurricanes
- 2
- Tropical storms
- 26
- Tornadoes
- 17
- EF3 or stronger
- 1
within 75 mi, since 1851
below hurricane strength
within 25 mi, since 1950
no recorded deaths
What the records show for Thornton
The strongest storm to pass near Thornton was an unnamed storm in 1869, a Category 1 hurricane with 85 mph winds when its centre passed 51 miles away. The closest pass by a hurricane was Carol in 1954, whose centre came within 18 miles. The record near Thornton begins with an unnamed storm in 1858; the most recent system was Isaias in 2020, a tropical storm 71 miles away. The busiest decade was the 1890s, with 6 systems. Of the 28 systems, 2 have come since 2000. Of the 142 New Hampshire cities on this site, 89% have more hurricanes within 75 miles than Thornton. The strongest of the 17 tornadoes within 25 miles was an F3 on August 25, 1969; its path came within 4 miles. Of the 17, one had a path within 5 miles of the city centre, and 6 have come since 2000. July and August have had the most tornadoes, 6 each. The most recent tornado was on June 18, 2018. Of the 142 New Hampshire cities, 88% have more tornadoes within 25 miles than Thornton. Hail has been reported within 10 miles 8 times since 1969, with stones up to 2 inches (hen egg size). Of the 142 New Hampshire cities, 99% have more hail reports within 10 miles than Thornton.
Compare Thornton's storm record with another city →
Tropical storms and hurricanes near Thornton
| Year | Storm | Closest | Strength when closest | Peak |
|---|---|---|---|---|
| 2020 | IsaiasAug 5 | 71 mi | Tropical storm (51 mph) | Category 1 |
| 2011 | IreneAug 28 | 29 mi | Tropical storm (52 mph) | Category 3 |
| 1999 | FloydSep 17 | 67 mi | Tropical storm (52 mph) | Category 4 |
| 1985 | GloriaSep 27 | 17 mi | Tropical storm (71 mph) | Category 4 |
| 1979 | DavidSep 6 | 19 mi | Tropical storm (49 mph) | Category 5 |
| 1971 | DoriaAug 28 | 3 mi | Tropical storm (52 mph) | Tropical storm |
| 1968 | Unnamed 1968 stormSep 11 | 34 mi | Tropical storm (52 mph) | Tropical storm |
| 1961 | Unnamed 1961 stormSep 15 | 56 mi | Tropical storm (68 mph) | Tropical storm |
| 1960 | DonnaSep 13 | 52 mi | Tropical storm (69 mph) | Category 4 |
| 1960 | BrendaJul 31 | 35 mi | Tropical storm (45 mph) | Tropical storm |
| 1954 | CarolAug 31 | 18 mi | Category 1 (83 mph) | Category 3 |
| 1949 | Unnamed 1949 stormAug 29 | 24 mi | Tropical storm (52 mph) | Category 4 |
| 1934 | Unnamed 1934 stormSep 9 | 36 mi | Tropical storm (44 mph) | Category 2 |
| 1923 | Unnamed 1923 stormOct 19 | 2 mi | Tropical storm (44 mph) | Tropical storm |
| 1916 | Unnamed 1916 stormMay 17 | 42 mi | Tropical storm (53 mph) | Tropical storm |
| 1908 | Unnamed 1908 stormMay 31 | 63 mi | Tropical storm (40 mph) | Category 1 |
| 1899 | Unnamed 1899 stormNov 1 | 5 mi | Tropical storm (52 mph) | Category 2 |
| 1897 | Unnamed 1897 stormSep 24 | 67 mi | Tropical storm (40 mph) | Tropical storm |
| 1896 | Unnamed 1896 stormSep 11 | 73 mi | Tropical storm (54 mph) | Category 3 |
| 1894 | Unnamed 1894 stormOct 10 | 41 mi | Tropical storm (56 mph) | Category 3 |
| 1893 | Unnamed 1893 stormAug 29 | 16 mi | Tropical storm (59 mph) | Category 3 |
| 1893 | Unnamed 1893 stormAug 24 | 26 mi | Tropical storm (67 mph) | Category 3 |
| 1878 | Unnamed 1878 stormOct 24 | 72 mi | Tropical storm (58 mph) | Category 2 |
| 1874 | Unnamed 1874 stormSep 30 | 50 mi | Tropical storm (69 mph) | Category 1 |
| 1869 | Unnamed 1869 stormSep 9 | 51 mi | Category 1 (85 mph) | Category 3 |
| 1861 | Unnamed 1861 stormNov 3 | 69 mi | Tropical storm (58 mph) | Category 1 |
| 1861 | Unnamed 1861 stormSep 28 | 72 mi | Tropical storm (58 mph) | Category 1 |
| 1858 | Unnamed 1858 stormSep 16 | 40 mi | Tropical storm (68 mph) | Category 2 |
Strength is the sustained wind on the track at the closest point, which is not the wind felt in Thornton: a hurricane's worst winds sit within a few dozen miles of its centre, and inland cities are usually past that.
Tornadoes within 25 miles of Thornton
By decade
- 2010s5
- 2000s1
- 1990s1
- 1970s6
- 1960s4(1 EF3+)
| Date | Rating | Distance | Path | Killed / injured |
|---|---|---|---|---|
| Aug 25, 1969 | F3 | 4 mi | 5.7 mi | 0 / 0 |
| Aug 11, 1966 | F2 | 18 mi | 9 mi | 0 / 0 |
| Jul 23, 1995 | F1 | 19 mi | 0.5 mi | 0 / 0 |
| Jul 23, 1978 | F1 | 23 mi | 0.2 mi | 0 / 0 |
| Aug 15, 1976 | F1 | 18 mi | 0.1 mi | 0 / 5 |
| Aug 9, 1972 | F1 | 21 mi | 0.1 mi | 0 / 0 |
| Jul 28, 1970 | F1 | 21 mi | 0.1 mi | 0 / 0 |
| Jul 14, 1963 | F1 | 15 mi | 0.1 mi | 0 / 0 |
| Jun 18, 2018 | EF0 | 12 mi | 0.2 mi | 0 / 0 |
| Jun 18, 2018 | EF0 | 16 mi | 9.45 mi | 0 / 0 |
| Jul 24, 2014 | EF0 | 23 mi | 0.02 mi | 0 / 0 |
| Jul 17, 2012 | EF0 | 21 mi | 0.46 mi | 0 / 0 |
The strongest 12 of 17, by rating and then by deaths. Ratings before February 2007 are on the original Fujita scale.
Hail in Thornton
The Storm Prediction Center has 8 hail reports within 10 miles of Thornton since 1969. All were 1 inch across or larger, and one reached 2 inches. The largest, 2 inches (hen egg size), fell on August 25, 1969. The most recent report is from July 3, 2025.
Source: NOAA Storm Prediction Center severe weather reports, data through 2025.
Weather by month in Thornton
The nearest NOAA station with 1991–2020 climate normals is Plymouth, NH, 10 miles south of Thornton at 660 feet. July is the warmest, with an average high of 80°F and low of 54°F; January is the coolest, at 29°F and 7°F. October is the wettest at 4.6 inches of precipitation on average and February the driest at 2.6 inches; the year adds up to 44.5 inches over 84 days with at least a tenth of an inch. June to November, the hurricane season months, bring 55% of the year's precipitation (24.5 of 44.5 inches); the other six months are drier. September has brought the most of the 28 tropical systems that passed within 75 miles (13); a normal September there has highs of 72°F and 3.6 inches of precipitation. Highs reach 90°F on about 5 days a year, almost all from June to August. Lows fall below freezing on about 196 nights a year. Snowfall averages 68.3 inches a year, most of it in January. That 44.5 inches is more than at 16 of the 39 New Hampshire stations used on this site (41%). Moultonborough, 19 miles southeast, has its own station (Lakeport 2, NH): 45.7 inches a year, 1.2 more than here, and a July average high of 82°F against 80°F.
| Month | High °F | Low °F | Precip. in | Days ≥ 0.1" | Snow in |
|---|---|---|---|---|---|
| Jan | 29 | 7 | 3.2 | 7 | 18.0 |
| Feb | 33 | 8 | 2.6 | 6 | 15.7 |
| Mar | 41 | 18 | 3.2 | 7 | 13.5 |
| Apr | 55 | 29 | 3.3 | 7 | 3.4 |
| May | 67 | 39 | 3.7 | 8 | 0.0 |
| Jun | 75 | 49 | 4.4 | 8 | 0.0 |
| Jul | 80 | 54 | 4.5 | 8 | 0.0 |
| Aug | 79 | 52 | 3.8 | 7 | 0.0 |
| Sep | 72 | 45 | 3.6 | 6 | 0.0 |
| Oct | 58 | 34 | 4.6 | 7 | 0.3 |
| Nov | 46 | 25 | 3.6 | 7 | 3.2 |
| Dec | 34 | 15 | 4.0 | 7 | 14.2 |
| Year | 56 | 31 | 44.5 | 84 | 68.3 |
Averages for 1991–2020 at Plymouth, NH (660 ft), from NOAA NCEI U.S. Climate Normals. Normals describe the station; the farther a place is from it, and the bigger the difference in height, the more its weather can differ.
Floods, thunderstorm wind and lightning near Thornton
Since 1996, the National Weather Service has logged 78 flood, rain, thunderstorm wind and lightning events that began within 10 miles of Thornton: 34 floods, 28 thunderstorm wind reports and 16 flash floods. None is recorded as killing or injuring anyone; the NWS estimated $4.4 million in property and crop damage. The strongest thunderstorm gust on record here was 60 mph, on July 20, 2015. August has had the most flash floods, 6 of 16. Of the 141 New Hampshire cities on this site with a flash flood on record, 113 have had fewer than Thornton.
August 28, 2011: flash flood 9 miles from the centre of Thornton — $3.0 million damage.
NWS: “Heavy rain from Tropical Storm Irene caused serious flash flooding in Lincoln.”
August 28, 2011: flood 6 miles from the centre of Thornton — $300,000 damage.
NWS: “5 ft.”
August 28, 2011: flash flood 7 miles from the centre of Thornton — $300,000 damage.
NWS: “Heavy rain from Tropical Storm Irene caused flash flooding in Waterville Valley.”
Source: NOAA NCEI Storm Events Database, events whose starting point is on record, 1996 to June 30, 2026. Damage is the NWS estimate in the dollars of the year, not insured losses, and NWS notes that some reports are unverified.
Flood insurance claims, disaster declarations and FEMA risk ratings
Flood insurance policyholders in Thornton's ZIP code 03285 have filed 16 claims with the National Flood Insurance Program since 1995, and were paid $461,000 for buildings and contents, in the dollars of each year. 50% of the claims carry the name of a storm or flood event; the rest have no event name. Of the 60 New Hampshire cities on this site with 10 or more claims, 12 have fewer than Thornton.
Grafton County, which includes Thornton, has been named in 40 federal disaster or emergency declarations since 1973, 29 of them major disasters (by incident: 17 severe storms, 8 floods, 6 hurricanes, 5 snowstorms). The latest major disaster declaration was Severe Storm and Flooding, on August 20, 2024. FEMA's National Risk Index gives Grafton County a Relatively Moderate rating for natural hazard risk overall; by hazard: Relatively Moderate for inland flooding and lightning; Relatively Low for hurricanes, strong wind and heat waves; Very Low for tornadoes and hail. It models the county's expected loss from all 18 hazards it covers at $50.4 million a year, the 3rd highest of 10 New Hampshire counties; of the hazards above, the largest share, $43.0 million (85%), is from inland flooding.
Claims: FEMA, OpenFEMA Dataset FIMA NFIP Redacted Claims – v3, summed over ZIP codes; payments in the dollars of each year, not adjusted for inflation. Declarations: Disaster Declarations Summaries – v2, by county. Retrieved October 25, 2026. 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).
Risk ratings: FEMA, National Risk Index county table, December 2025 (v1.20), retrieved October 26, 2026; ratings compare counties nationwide, are meant for planning and are no substitute for a local risk assessment. This product uses the Federal Emergency Management Agency's National Risk Index dataset API or downloadable datasets 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).
What counts as a pass, the distances and the sources: how this storm history is built.