Flash Flood — Hillsborough, New Hampshire

2025-06-06 · near Hillsboro Lower Vlg, Hillsborough, New Hampshire

Event narrative

Repeating thunderstorms brought up to 4 inches of rainfall to the Antrim area between 3 pm and 7 pm on June 6. The high rainfall rates on nearly saturated ground resulted in flooding of Routes 31 and 9, with some minor shoulder damage. Local roads were more impacted with minor to moderate washouts along Reed Carr, Liberty Farm, Stacy Hill, and Farmstead Roads. The most significant flooding of the event occurred along Mountainside Drive off Franklin Pierce Lake where runoff eroded a driveway to the home foundation, damaging 2 vehicles.

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 → (43.1049, -71.9342)

Source: NOAA Storm Events Database, event_id 1252505. Narrative written by the NWS forecast office that issued the report.