New Hampshire, 2025

Flash Flooding and Hail in New Hampshire, August 13, 2025

August 13, 2025 · NWS GYX · 10 events in 2 counties and zones

The region was experiencing well above normal temperatures, with high temperatures reaching the low to mid-90s. This created a very warm, humid, and unstable atmosphere.

Where it happened

Every event with a place to put it. Tap one for its entry below.

  • Tornadoes
  • Tropical storms and surge
  • Floods
  • Wind
  • Hail
  • Winter weather
  • Heat and drought
  • Cold
  • Fire, smoke and dust
  • Marine and coastal
  • Other

Open the live radar over this ground

The toll

Deaths
0
Injuries
0
Property damage
$4,000
Crop damage
None recorded
Events
10

Deaths and injuries are direct and indirect together, as the offices filed them. Damage is property and crops in the dollars of the year, not adjusted for inflation, and only where an office estimated it.

What happened

The episode as NWS GYX wrote it up.

The region was experiencing well above normal temperatures, with high temperatures reaching the low to mid-90s. This created a very warm, humid, and unstable atmosphere. A pre-frontal surface trough moved into NH on the afternoon of August 13th, triggering numerous thunderstorms, a few of the storms became severe in nature. In addition, very heavy rain fell in Nashua area, causing some minor urban flooding.

The radar

The Boston radar (KBOX), 109 km away, was scanning. The volume nearest the first event began at 21:08 UTC.

Open the radar archive at this moment

Event by event

6 thunderstorm wind, 2 hail, 2 flash flood. Local standard time, as filed.

Hail, Hillsborough

When
August 13, 4:08 PM EST to 4:13 PM EST
Where
Hillsborough County, Baboosic
Measured
1 in hail
Reported by
Amateur Radio
Coordinates
42.880, -71.580

A severe thunderstorm dropped hail the size of quarters that fell for about 5 minutes in Amherst.

Thunderstorm Wind, Hillsborough

When
August 13, 4:25 PM EST to 4:30 PM EST
Where
Hillsborough County, 0.86 mi NE of Baboosic
Measured
50 kt (58 mph) estimated gust
Reported by
Amateur Radio
Coordinates
42.890, -71.570

A severe thunderstorm outflow boundary downed a tree on wires and a second tree down on car on Carter Road north of Amherst.

Thunderstorm Wind, Hillsborough

When
August 13, 4:30 PM EST to 4:35 PM EST
Where
Hillsborough County, 0.51 mi W of Goffstown
Measured
50 kt (58 mph) estimated gust
Property damage
$2,000
Reported by
Amateur Radio
Coordinates
43.020, -71.610

A severe thunderstorm outflow boundary downed a large tree on top of vehicle in Goffstown.

Thunderstorm Wind, Hillsborough

When
August 13, 4:38 PM EST to 4:44 PM EST
Where
Hillsborough County, 0.86 mi NW of Mt Vernon
Measured
50 kt (58 mph) estimated gust
Reported by
Amateur Radio
Coordinates
42.910, -71.680

A severe thunderstorm outflow boundary downed numerous trees north of Mount Vernon, partially blocking traffic on N. Main St.

Thunderstorm Wind, Hillsborough

When
August 13, 4:45 PM EST to 4:50 PM EST
Where
Hillsborough County, 1.47 mi NNE of Pine Hill
Measured
50 kt (58 mph) estimated gust
Property damage
$2,000
Reported by
Public
Coordinates
42.790, -71.490

A severe thunderstorm outflow boundary downed a tree damaging a garage on Tinker Rd. in Nashua.

Hail, Cheshire

When
August 13, 4:55 PM EST to 4:59 PM EST
Where
Cheshire County, 0.86 mi NW of Webb
Measured
1.25 in hail
Reported by
Trained Spotter
Coordinates
42.880, -72.230

A severe thunderstorm dropped hail the size of ping pongs for around 5 minutes in Swanzey.

Thunderstorm Wind, Cheshire

When
August 13, 5:05 PM EST to 5:10 PM EST
Where
Cheshire County, 2.05 mi NE of Troy
Measured
50 kt (58 mph) estimated gust
Reported by
Amateur Radio
Coordinates
42.850, -72.150

A severe thunderstorm outflow boundary downed trees on wires along Jaffrey Rd. in Troy.

Thunderstorm Wind, Cheshire

When
August 13, 5:38 PM EST to 5:43 PM EST
Where
Cheshire County, 0.86 mi SE of Jaffrey
Measured
50 kt (58 mph) estimated gust
Reported by
Trained Spotter
Coordinates
42.810, -72.020

A severe thunderstorm outflow boundary downed 12 trees and along with numerous branches down across Jaffrey.

Flash Flood, Hillsborough

When
August 13, 6:26 PM EST to 6:45 PM EST
Where
Hillsborough County, 1.52 mi E of Pine Hill to 1.49 mi E of Pine Hill
Cause
Heavy Rain
Reported by
Trained Spotter
Coordinates
42.770, -71.470

Very heavy rainfall associated with a severe thunderstorm dropped 2+ inches of rain in under an hour across the Nashua City area. The rainfall rates caused urban flooding with manhole covers popping off and flooding of Amherst Street in Nashua.

Flash Flood, Hillsborough

When
August 13, 6:47 PM EST to 6:58 PM EST
Where
Hillsborough County, 1.56 mi SSE of Pine Hill to 1.63 mi SSE of Pine Hill
Cause
Heavy Rain
Reported by
Amateur Radio
Coordinates
42.750, -71.486

Very heavy rainfall associated with a severe thunderstorm dropped 2+ inches of rain in under an hour across the Nashua City area. Library Street flooded with water up to car headlights.

What these are

Hail
Hail three-quarters of an inch or larger, or smaller hail that caused damage, filed with the largest stone measured.
Thunderstorm Wind
Winds from a thunderstorm of 50 knots (58 mph) or more, or lower winds that caused damage or casualties. Measured gusts are marked MG, estimated EG.
Flash Flood
Flooding that begins within six hours of the rain that causes it, or of a dam or levee failure or ice jam release, often with deadly speed.

After NWS Directive 10-1605, the rules offices file Storm Data by.

The same day elsewhere

More

Every storm in New Hampshire in 2025Every state in 2025This day in weather historyWarnings in New Hampshire, August 2025

Sources

NOAA National Centers for Environmental Information, Storm Events Database, compiled from the National Weather Service’s monthly Storm Data. Complete through 2026-06; NCEI adds each month about 75 days after it ends and revises past years a few times a year. Rebuilt 2026-09-24. Each event’s entry at NCEI: 1292529, 1292533, 1292534, 1292535, 1292537, 1292532, 1292539, 1292540, 1292525, 1292528.