Flood events in Merrimack County, New Hampshire The flood events on record, by date and by year
This page is a county record of past events and claims. It does not show the flood zone or the risk of an address. For the flood map of an address, use FEMA's address search (opens in a new tab).
NCEI has 111 flood events on record for Merrimack County, New Hampshire, from 1996 through 30 Jun 2026.
The newest flood event on record is on 6 Jun 2025.
From 2016 through 2025, NCEI has 40 flood events on record for the county.
The NWS collects event reports from a variety of sources, which include (but are not limited to): county, state, and federal emergency management officials, local law enforcement officials, SKYWARN spotters, NWS damage surveys, newspaper clipping services, the insurance industry, and the general public, among others.
The National Weather Service reports property and crop damage estimates using available data at the time of event reporting. These values should therefore be considered broad estimates. Damage amounts are not adjusted for inflation.
Zone (NWS Forecast Zone): A zone is a geographic area defined by the NWS for issuing forecasts, watches, and warnings. While zones often align with counties, they can also represent smaller or subdivided areas within a county to account for differences in weather conditions, such as elevation or proximity to water. Larger-scale events—such as heat, cold, drought, and winter storms—are typically recorded by zone.
The words of the agency. Source: NOAA NCEI, Storm Events Database, page "Frequently Asked Questions", copied on .
Date of the data: NCEI storm events through . Event types on this page: Flood, Flash Flood, Coastal Flood, Lakeshore Flood.
Newest flood events on record
Flash Flood
2 miles S of WEST HENNIKER
Flood
2 miles NE of DAVISVILLE
Flood
2 miles WSW of CONTOOCOOK
Flood
At DAVISVILLE
Flash Flood
At WATERLOO
Flood
1 mile NE of NORTH CHICHESTER
Flash Flood
4 miles SSE of SOUTH HOOKSETT
Flash Flood
At DANBURY
Flood
At HENNIKER
Flood
2 miles N of WEST SALISBURY
Flood
1 mile NE of DANBURY
Flash Flood
At HENNIKER
Flood
1 mile ENE of NORTH CHICHESTER
Flash Flood
1 mile ENE of GERRISH
Flood
At WEST SALISBURY
Flood
At DAVISVILLE
Flood
2 miles E of PITTSFIELD. Damage estimate: $25 thousand
Flood
At PEMBROKE
Flood
At NORTH CHICHESTER
Flash Flood
1 mile SSW of NEWBURY. Damage estimate: $35 thousand
Flash Flood
2 miles SSW of WEST SALISBURY. Damage estimate: $20 thousand
Flash Flood
1 mile NW of SHAKER VLG. Damage estimate: $20 thousand
Flash Flood
2 miles NNW of LONDON CENTER. Damage estimate: $15 thousand
Flood
1 mile WNW of DAVISVILLE
Flood
1 mile NE of NORTH CHICHESTER
A place is the text of the NCEI record: a distance and a direction from a reference place. The site does not show a place text that names a private property or reads as a person. NCEI gives no magnitude for this hazard.
Flood events by year
| Decade | Year that ends in 0 | Year that ends in 1 | Year that ends in 2 | Year that ends in 3 | Year that ends in 4 | Year that ends in 5 | Year that ends in 6 | Year that ends in 7 | Year that ends in 8 | Year that ends in 9 | All |
|---|---|---|---|---|---|---|---|---|---|---|---|
| 1950s | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
| 1960s | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
| 1970s | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
| 1980s | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
| 1990s | 0 | 0 | 0 | 0 | 0 | 0 | 1 | 0 | 2 | 1 | 4 |
| 2000s | 1 | 2 | 0 | 1 | 1 | 7 | 9 | 4 | 5 | 5 | 35 |
| 2010s | 12 | 8 | 0 | 3 | 7 | 2 | 1 | 4 | 7 | 3 | 47 |
| 2020s | 2 | 4 | 5 | 10 | 0 | 4 | 0 (part of the year) | 25 |
A darker cell has a larger count. The number is in each cell.
Flood and flash flood events are on record from 1996. The year 2026 has the events through 30 Jun 2026 only.
By month, all years
- Jan3 events
- Feb3 events
- Mar12 events
- Apr19 events
- May8 events
- Jun10 events
- Jul14 events
- Aug11 events
- Sep6 events
- Oct8 events
- Nov6 events
- Dec11 events
Beside the other counties
| Measure | Merrimack | All counties of New Hampshire | All counties of the United States |
|---|---|---|---|
| Flood events, 1996 to 2026 | 111 | 869 | 177,902 |
| Events for each 100 square miles | 11.9 | 9.7 | 5.0 |
| Events for each 10,000 residents | 7.2 | 6.3 | 5.4 |
The columns for the state and the United States total the counties. They count the events of each county in the same way as the county column. A forecast zone with another name than a county counts for the state only.
More flood events on record
| Date | Event type | Magnitude | Damage estimate | Deaths | Injuries | On record for |
|---|---|---|---|---|---|---|
| Flood | not recorded | none | 0 | 0 | County | |
| Flood | not recorded | none | 0 | 0 | County | |
| Flood | not recorded | none | 0 | 0 | County | |
| Flood | not recorded | none | 0 | 0 | County | |
| Flood | not recorded | none | 0 | 0 | County | |
| Flood | not recorded | none | 0 | 0 | County | |
| Flash Flood | not recorded | none | 0 | 0 | County | |
| Flash Flood | not recorded | none | 0 | 0 | County | |
| Flood | not recorded | none | 0 | 0 | County | |
| Flood | not recorded | none | 0 | 0 | County | |
| Flood | not recorded | none | 0 | 0 | County | |
| Flood | not recorded | none | 0 | 0 | County | |
| Flood | not recorded | none | 0 | 0 | County | |
| Flood | not recorded | none | 0 | 0 | County | |
| Flood | not recorded | none | 0 | 0 | County | |
| Flash Flood | not recorded | $100 thousand | 0 | 0 | County | |
| Flood | not recorded | none | 0 | 0 | County | |
| Flash Flood | not recorded | $25 thousand | 0 | 0 | County | |
| Flash Flood | not recorded | $25 thousand | 0 | 0 | County | |
| Flash Flood | not recorded | $50 thousand | 0 | 0 | County | |
| Flood | not recorded | none | 0 | 0 | County | |
| Flood | not recorded | none | 0 | 0 | County | |
| Flood | not recorded | none | 0 | 0 | County | |
| Flood | not recorded | none | 0 | 0 | County | |
| Flash Flood | not recorded | $10 thousand | 0 | 0 | County | |
| Flash Flood | not recorded | $25 thousand | 0 | 0 | County | |
| Flash Flood | not recorded | $15 thousand | 0 | 0 | County | |
| Flood | not recorded | none | 0 | 0 | County | |
| Flood | not recorded | none | 0 | 0 | County | |
| Flood | not recorded | $900 thousand | 0 | 0 | County | |
| Flood | not recorded | none | 0 | 0 | County | |
| Flood | not recorded | none | 0 | 0 | County | |
| Flood | not recorded | none | 0 | 0 | County | |
| Flood | not recorded | none | 0 | 0 | County | |
| Flood | not recorded | $6 thousand | 0 | 0 | County | |
| Flood | not recorded | none | 0 | 0 | County | |
| Flood | not recorded | none | 0 | 0 | County | |
| Flood | not recorded | none | 0 | 0 | County | |
| Flood | not recorded | none | 0 | 0 | County | |
| Flood | not recorded | none | 0 | 0 | County | |
| Flood | not recorded | none | 0 | 0 | County | |
| Flood | not recorded | none | 0 | 0 | County | |
| Flood | not recorded | none | 0 | 0 | County | |
| Flood | not recorded | none | 0 | 0 | County | |
| Flood | not recorded | $440 thousand | 0 | 0 | County | |
| Flood | not recorded | $100 thousand | 0 | 0 | County | |
| Flood | not recorded | $1.7 million | 0 | 0 | County | |
| Flood | not recorded | none | 0 | 0 | County | |
| Flash Flood | not recorded | $50 thousand | 0 | 0 | County | |
| Flash Flood | not recorded | $50 thousand | 0 | 0 | County | |
| Flood | not recorded | none | 0 | 0 | County | |
| Flood | not recorded | none | 0 | 0 | County | |
| Flood | not recorded | $25 thousand | 0 | 0 | County | |
| Flood | not recorded | $50 thousand | 0 | 0 | County | |
| Flood | not recorded | $10 thousand | 0 | 0 | County | |
| Flood | not recorded | $20 thousand | 0 | 0 | County | |
| Flash Flood | not recorded | $50 thousand | 0 | 0 | County | |
| Flood | not recorded | none | 0 | 0 | County | |
| Flood | not recorded | none | 0 | 0 | County | |
| Flood | not recorded | none | 0 | 0 | County | |
| Flood | not recorded | $1.0 million | 0 | 0 | County | |
| Flood | not recorded | $1 thousand | 0 | 0 | County | |
| Flood | not recorded | $1 thousand | 0 | 0 | County | |
| Flood | not recorded | none | 0 | 0 | County | |
| Flood | not recorded | none | 0 | 0 | County | |
| Flood | not recorded | none | 0 | 0 | County | |
| Flood | not recorded | none | 0 | 0 | County | |
| Flood | not recorded | none | 0 | 0 | County | |
| Flood | not recorded | none | 0 | 0 | County | |
| Flood | not recorded | $750 thousand | 0 | 0 | County | |
| Flood | not recorded | none | 0 | 0 | Forecast zone | |
| Flood | not recorded | $10 thousand | 0 | 0 | Forecast zone | |
| Flood | not recorded | $100 thousand | 0 | 0 | Forecast zone | |
| Flood | not recorded | $10 thousand | 0 | 0 | Forecast zone | |
| Flood | not recorded | $1.0 million | 0 | 0 | Forecast zone | |
| Flash Flood | not recorded | $150 thousand | 0 | 0 | County | |
| Flood | not recorded | $250 thousand | 0 | 0 | Forecast zone | |
| Flood | not recorded | none | 0 | 0 | Forecast zone | |
| Flash Flood | not recorded | none | 0 | 0 | County | |
| Flood | not recorded | none | 0 | 0 | Forecast zone | |
| Flash Flood | not recorded | none | 0 | 0 | County | |
| Flash Flood | not recorded | none | 0 | 0 | County | |
| Flash Flood | not recorded | none | 0 | 0 | Forecast zone | |
| Flash Flood | not recorded | $200 thousand | 0 | 0 | County | |
| Flash Flood | not recorded | $100 thousand | 0 | 0 | County | |
| Flash Flood | not recorded | $2.2 million | 0 | 0 | County |
The table has all other events on record. A damage figure is an estimate in the NCEI record.
Official channels
- NCEI Storm Events Database (opens in a new tab)Search the full NCEI record by state, county and date.
- National Weather Service: Gray - Portland, ME (opens in a new tab)The forecast office that issues the weather warnings for the county.
- FEMA Flood Map Service Center: Search By Address (opens in a new tab)Search an address to see its flood map. This site has no flood-zone data.
These links open the pages of the agencies. The site checked the links on .
Cite this page
County Hazards. "Flood events on record for Merrimack County, New Hampshire". https://countyhazards.com/county/nh/merrimack/flood/. Data: NOAA NCEI Storm Events Database through 30 Jun 2026. Page made on .
Questions
- Which month has the most flood events on record for Merrimack County?
- April has 19 of the 111 flood events on record from 1996 through 30 Jun 2026.
- How many flood events are on record for New Hampshire?
- NCEI has 1,048 flood events on record for New Hampshire from 1996 through 30 Jun 2026. That count has every forecast zone of the state.
- How does Merrimack County compare with the other counties of New Hampshire?
- The counties of New Hampshire have 9.7 flood events for each 100 square miles. Merrimack County has 11.9.
- Why are some flood events on record for a forecast zone?
- NCEI records some event types for a National Weather Service forecast zone and not for a county. This page counts a zone event when the zone has the name of the county.