In 2025, fire departments serving Merrimack responded to 248 fire and hazmat incidents — from cooking fires to gas leaks to a single $130K building blaze. Here's the full picture.
Gas leak (natural gas or LPG) lead by count. Building fires lead by dollars. Together the top five categories make up about 57% of all calls.
Sep peaks. Oct dips. Watch for the typical fall climb starting in October.
1,166 incidents 2021–2025. Peak year was 2023. $885K cumulative property loss. 1 civilian deaths.
| Year | Incidents | YoY | |
|---|---|---|---|
| 2021 | 177 | — | |
| 2022 | 189 | +6.8% | |
| 2023 | 322 | +70.4% | |
| 2024 | 230 | -28.6% | |
| 2025 | 248 | +7.8% |
For the 5 building fires Merrimack departments responded to in 2025, here's how they were classified once investigators were finished.
NFIRS Area of Origin (AREA_ORIG) for the 107 building fires investigators classified across 2021–2025. The room or location where ignition occurred — kitchens, bedrooms, exterior, vehicle areas — tells you where to focus prevention.
| # | Area of origin | Count | Share | |
|---|---|---|---|---|
| 1 | Engine area, running gear, wheel area | 16 | 15.0% | |
| 2 | Undetermined | 16 | 15.0% | |
| 3 | Outside area, other | 14 | 13.1% | |
| 4 | Wildland, woods | 10 | 9.3% | |
| 5 | Highway, parking lot, street: on or near | 9 | 8.4% | |
| 6 | Vehicle area, other | 8 | 7.5% | |
| 7 | Open area - outside; included are farmland, field | 5 | 4.7% | |
| 8 | Other | 4 | 3.7% | |
| 9 | Bedroom - < 5 persons; included are jail or prison | 4 | 3.7% | |
| 10 | Cooking area, kitchen | 3 | 2.8% | |
| 11 | All other areas | 18 | 16.8% |
NFIRS Heat Source (HEAT_SOURC) — the physical thing that started it. Spark or ember from operating equipment, an open flame, smoking materials, or hot embers from a fireplace are the leading culprits nationwide. Here's the Merrimack mix.
| # | Heat source | Count | Share | |
|---|---|---|---|---|
| 1 | Undetermined | 43 | 40.2% | |
| 2 | Radiated, conducted heat from operating equipment | 10 | 9.3% | |
| 3 | Heat source: other | 9 | 8.4% | |
| 4 | Spark, ember or flame from operating equipment | 5 | 4.7% | |
| 5 | Arcing | 5 | 4.7% | |
| 6 | Cigarette | 4 | 3.7% | |
| 7 | Heat from powered equipment, other | 3 | 2.8% | |
| 8 | Hot ember or ash | 3 | 2.8% | |
| 9 | Lightning | 3 | 2.8% | |
| 10 | Heat from direct flame, convection currents | 3 | 2.8% | |
| 11 | All other sources | 19 | 17.8% |
Largest single-incident property losses reported by Merrimack departments in 2025. These 8 fires alone account for 100% of the city's annual total.
| # | Property loss | Type | Severity | Status |
|---|---|---|---|---|
| 1 | $130,000 | Road freight or transport vehicle fire | Significant | Investigated |
| 2 | $40,000 | Passenger vehicle fire | Significant | Investigated |
| 3 | $10,000 | Outside equipment fire | Significant | Investigated |
| 4 | $5,000 | Fuel burner/boiler malfunction, fire confined | Significant | Investigated |
| 5 | $5,000 | Outside rubbish, trash or waste fire | Significant | Investigated |
| 6 | $2,500 | Building fires | Significant | Investigated |
| 7 | $1,000 | Passenger vehicle fire | Significant | Investigated |
| 8 | $1 | Brush, or brush and grass mixture fire | Significant | Investigated |
Per-capita rates let us compare apples to apples. Merrimack sits above the national average for incidents per resident.
Top 25 wildfires (1992+) in the FPA-FOD ignitions database, scaled by acres. 4,061 acres burned in this 50-mile radius. Each dot is a fire — bigger dots burned more land.
| Year | Cause | Acres | Distance | |
|---|---|---|---|---|
| 2005 | Missing data/not specified/undetermined | 800 | 25.5 mi | |
| 2008 | Missing data/not specified/undetermined | 700 | 25.5 mi | |
| 2003 | Missing data/not specified/undetermined | 300 | 43.2 mi | |
| 2002 | Missing data/not specified/undetermined | 300 | 25.5 mi | |
| 2014 | Missing data/not specified/undetermined | 256 | 25.6 mi | |
| 2015 | Missing data/not specified/undetermined | 250 | 25.2 mi | |
| 2016 | Arson/incendiarism | 190 | 31.5 mi | |
| 2007 | Missing data/not specified/undetermined | 186 | 30.1 mi | |
| 2016 | Missing data/not specified/undetermined | 172 | 25.4 mi | |
| 2004 | Missing data/not specified/undetermined | 120 | 39.2 mi | |
| 2015 | Missing data/not specified/undetermined | 92 | 41.1 mi | |
| 2014 | Missing data/not specified/undetermined | 90 | 38.0 mi |
Top 1 ZIP codes by NFIRS incident count across 2021–2025. Each ZIP has its own fire profile — dive in for neighborhood-level context.
| # | ZIP | 5-yr incidents | |
|---|---|---|---|
| 1 | 03054 | 1,166 |
Six New Hampshire cities with population within ±25% of Merrimack. Useful comparison targets — same state, similar size, different fire profile.
1 departments report to NFIRS for incidents in Merrimack.
A 30-minute weekend can cut your home's exposure substantially. These four checklists are a good starting point.
Numbers reflect incidents reported by participating fire departments to the National Fire Incident Reporting System (NFIRS) Public Data Release for calendar year 2025. NFIRS is voluntary — about 23,000 of roughly 30,000 US fire departments report — so totals are a strong indicator, not a complete census. Per-capita comparisons use 2023 ACS population estimates. Wildland fire data complements NFIRS with NIFC and USFS perimeters. Active-fire counts come from a dated NIFC snapshot, not a live feed.