Merrimack County weather alerts
There are no active weather alerts for Merrimack County, NH right now.
Since 2016 the National Weather Service has issued about 959 alerts that included Merrimack County, roughly 96 a year. The most common is the severe thunderstorm warning (175 from 2016 to 2025). The last tornado warning was issued on June 23, 2024. 7 tornadoes have touched down in the county since 1950.
Updated from the National Weather Service · lists refresh hourly; the live map loads current alerts directly from the NWS
No warnings, watches or advisories include Merrimack County at the moment. This page updates automatically when the National Weather Service issues one. Check neighboring Belknap County, Strafford County, Sullivan County, Rockingham County.
Merrimack County alert history
Alert events that included Merrimack County or its forecast zones, from the NWS warning archive.
| Alert type | 2016–2025 | 2026 | Last issued |
|---|---|---|---|
| Severe Thunderstorm Warning | 175 | 14 | July 16, 2026 |
| Winter Weather Advisory | 110 | 8 | March 22, 2026 |
| Flood Advisory | 85 | 2 | August 3, 2026 |
| Flood Warning | 69 | 1 | March 17, 2026 |
| Wind Advisory | 69 | 1 | March 17, 2026 |
| Flood Watch | 59 | 2 | July 29, 2026 |
| Winter Storm Watch | 55 | 1 | January 25, 2026 |
| Severe Thunderstorm Watch | 48 | 2 | July 15, 2026 |
| Winter Storm Warning | 48 | 3 | February 23, 2026 |
| Dense Fog Advisory | 46 | 0 | April 1, 2025 |
| Heat Advisory | 42 | 3 | July 14, 2026 |
| Flash Flood Warning | 31 | 1 | August 3, 2026 |
| Snow Squall Warning | 22 | 0 | December 4, 2025 |
| Frost Advisory | 19 | 1 | May 12, 2026 |
| Red Flag Warning | 18 | 0 | April 20, 2025 |
| Fire Weather Watch | 11 | 0 | April 27, 2021 |
| Cold Weather Advisory | 10 | 4 | February 9, 2026 |
| Freeze Warning | 7 | 0 | October 10, 2025 |
| Tornado Warning | 5 | 0 | June 23, 2024 |
| Extreme Cold Watch | 4 | 0 | February 3, 2023 |
| High Wind Warning | 4 | 0 | February 17, 2025 |
| Extreme Heat Watch | 4 | 1 | July 1, 2026 |
| Extreme Heat Warning | 4 | 1 | July 1, 2026 |
| Tornado Watch | 4 | 1 | June 18, 2026 |
| Extreme Cold Warning | 3 | 1 | February 7, 2026 |
| High Wind Watch | 3 | 0 | December 23, 2022 |
| Freeze Watch | 2 | 0 | October 10, 2025 |
| Tropical Storm Watch | 1 | 0 | August 3, 2020 |
| Tropical Storm Warning | 1 | 0 | August 3, 2020 |
Tornado history in Merrimack County
7 tornadoes have been recorded in Merrimack County since 1950, killing 1 people and injuring 12. That ranks 7 of 10 counties in New Hampshire. The most recent was on May 4, 2018 (rated EF1).
Strongest tornadoes in Merrimack County
| Date | Rating | County | Path length | Width | Deaths | Injuries |
|---|---|---|---|---|---|---|
| July 24, 2008 | EF2 | Rockingham County | 50.5 mi | 880 yd | 1 | 2 |
| July 6, 1999 | F2 | Merrimack County | 7.5 mi | 0 yd | 0 | 0 |
| May 4, 2018 | EF1 | Cheshire County | 37.6 mi | 300 yd | 0 | 0 |
| July 12, 1967 | F1 | Merrimack County | 0.5 mi | 30 yd | 0 | 5 |
| May 31, 1972 | F1 | Merrimack County | 0.1 mi | 50 yd | 0 | 0 |
Most recent tornadoes
| Date | Rating | County | Path length | Width | Deaths | Injuries |
|---|---|---|---|---|---|---|
| May 4, 2018 | EF1 | Cheshire County | 37.6 mi | 300 yd | 0 | 0 |
| July 30, 2015 | EF0 | Merrimack County | 0.4 mi | 100 yd | 0 | 0 |
| July 24, 2008 | EF2 | Rockingham County | 50.5 mi | 880 yd | 1 | 2 |
| July 6, 1999 | F2 | Merrimack County | 7.5 mi | 0 yd | 0 | 0 |
| August 15, 1976 | F1 | Merrimack County | 0.1 mi | 10 yd | 0 | 5 |
About Merrimack County
- Population: 157,869 (2024 estimate)
- State: New Hampshire
- NOAA Weather Radio SAME code: 033013 (how to use it)