In 2025, fire departments serving Thornton responded to 62 fire and hazmat incidents — from cooking fires to gas leaks to a single $100K building blaze. Here's the full picture.
Hazardous condition, other lead by count. Building fires lead by dollars. Together the top five categories make up about 53% of all calls.
Sep peaks. Apr dips. Watch for the typical fall climb starting in October.
277 incidents 2021–2025. Peak year was 2022. $262K cumulative property loss.
| Year | Incidents | YoY | |
|---|---|---|---|
| 2021 | 49 | — | |
| 2022 | 91 | +85.7% | |
| 2023* | 11 | — | |
| 2024 | 64 | — | |
| 2025 | 62 | -3.1% |
* Well below Thornton's usual volume. That almost always means one or more departments didn't submit a full year to NFIRS, not that fires dropped, so no year-over-year change is shown for it.
For the 5 building fires Thornton departments responded to in 2025, here's how they were classified once investigators were finished.
NFIRS Area of Origin (AREA_ORIG) for the 52 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 | Outside area, other | 11 | 21.2% | |
| 2 | Undetermined | 8 | 15.4% | |
| 3 | Other | 5 | 9.6% | |
| 4 | Cooking area, kitchen | 4 | 7.7% | |
| 5 | Engine area, running gear, wheel area | 3 | 5.8% | |
| 6 | Heating room or area, water heater area | 2 | 3.8% | |
| 7 | Vehicle area, other | 2 | 3.8% | |
| 8 | Operator/passenger area of transportation equip. | 2 | 3.8% | |
| 9 | Open area - outside; included are farmland, field | 2 | 3.8% | |
| 10 | Construction/renovation area | 2 | 3.8% | |
| 11 | All other areas | 11 | 21.2% |
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 Thornton mix.
| # | Heat source | Count | Share | |
|---|---|---|---|---|
| 1 | Undetermined | 15 | 28.8% | |
| 2 | Heat source: other | 6 | 11.5% | |
| 3 | Hot ember or ash | 6 | 11.5% | |
| 4 | Heat from powered equipment, other | 5 | 9.6% | |
| 5 | Spark, ember or flame from operating equipment | 5 | 9.6% | |
| 6 | Arcing | 5 | 9.6% | |
| 7 | Cigarette lighter | 3 | 5.8% | |
| 8 | Radiated, conducted heat from operating equipment | 2 | 3.8% | |
| 9 | Hot or smoldering object, other | 2 | 3.8% | |
| 10 | Heat from undetermined smoking material | 1 | 1.9% | |
| 11 | All other sources | 2 | 3.8% |
Largest single-incident property losses reported by Thornton departments in 2025. These 3 fires alone account for 100% of the city's annual total.
| # | Property loss | Type | Severity | Status |
|---|---|---|---|---|
| 1 | $100,000 | Passenger vehicle fire | Significant | Investigated |
| 2 | $60,000 | Building fires | Significant | Investigated |
| 3 | $2,500 | Fuel burner/boiler malfunction, fire confined | Significant | Investigated |
Per-capita rates let us compare apples to apples. Thornton sits above the national average for incidents per resident.
Top 25 wildfires (1992+) in the FPA-FOD ignitions database, scaled by acres. 1,728 acres burned in this 50-mile radius. Each dot is a fire — bigger dots burned more land.
| Year | Cause | Acres | Distance | |
|---|---|---|---|---|
| 2016 | Missing data/not specified/undetermined | 329 | 20.9 mi | |
| 2015 | Missing data/not specified/undetermined | 275 | 21.8 mi | |
| 2004 | Missing data/not specified/undetermined | 139 | 24.4 mi | |
| 2015 | Power generation/transmission/distribution | 137 | 40.7 mi | |
| 2012 | Debris and open burning | 120 | 33.7 mi | |
| 2015 | Missing data/not specified/undetermined | 92 | 33.2 mi | |
| 2017 | Missing data/not specified/undetermined | 72 | 10.6 mi | |
| 1995 | Missing data/not specified/undetermined | 60 | 34.8 mi | |
| 2015 | Missing data/not specified/undetermined | 59 | 48.8 mi | |
| 2008 | Missing data/not specified/undetermined | 54 | 12.7 mi | |
| 2000 | Debris and open burning | 51 | 49.2 mi | |
| 2016 | Missing data/not specified/undetermined | 50 | 37.9 mi |
Top 5 ZIP codes by NFIRS incident count across 2021–2025. Each ZIP has its own fire profile — dive in for neighborhood-level context.
Six New Hampshire cities with population within ±25% of Thornton. Useful comparison targets — same state, similar size, different fire profile.
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.