Flash Flood — Hillsborough, New Hampshire

2025-06-07 · near Peterborough, Hillsborough, New Hampshire

Event narrative

A burst of torrential rainfall over saturated ground resulted in a washout along Miller State Park Road on the afternoon of June 6. The rainfall estimated to have rainfall rates of 2 inches per hour cause excessive and rapid runoff over the high sloped terrain of the Pack Monadnock.

Wider weather episode

A stationary front stalled over southern New Hampshire on the evening of June 6 into midday on June 7th. Repeated rounds of heavy rain and thunderstorms brought up to 4 inches of rainfall to areas across Merrimack and Hillsborough Counties between 3 and 7 PM. The heavy rain with rates measured over 2 inches per hour at times, was sufficient to cause flash flooding with multiple roads flooded, some with washouts, and some property damage. Numerous severe thunderstorms also developed on the afternoon of June 6th as amble instability and moisture interacted with the stalled front boundary. Large hail and damaging winds were reported.

View location on OpenStreetMap → (42.8614, -71.8790)

Source: NOAA Storm Events Database, event_id 1252495. Narrative written by the NWS forecast office that issued the report.