In 2025, fire departments serving Ayer responded to 108 fire and hazmat incidents — from cooking fires to gas leaks to a single $200K building blaze. Here's the full picture.
Electrical wiring/equipment problem, other lead by count. Building fires lead by dollars. Together the top five categories make up about 56% of all calls.
Jun peaks. Feb dips. Watch for the typical fall climb starting in October.
515 incidents 2021–2025. Peak year was 2024. $4.2M cumulative property loss. 1 civilian deaths.
| Year | Incidents | YoY | |
|---|---|---|---|
| 2021 | 77 | — | |
| 2022 | 100 | +29.9% | |
| 2023 | 111 | +11.0% | |
| 2024 | 119 | +7.2% | |
| 2025 | 108 | -9.2% |
For the 12 building fires Ayer departments responded to in 2025, here's how they were classified once investigators were finished.
NFIRS Area of Origin (AREA_ORIG) for the 77 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 | 14 | 18.2% | |
| 2 | Undetermined | 9 | 11.7% | |
| 3 | Cooking area, kitchen | 7 | 9.1% | |
| 4 | Other | 6 | 7.8% | |
| 5 | Engine area, running gear, wheel area | 5 | 6.5% | |
| 6 | Railroad right of way: on or near | 4 | 5.2% | |
| 7 | Open area - outside; included are farmland, field | 4 | 5.2% | |
| 8 | Wildland, woods | 4 | 5.2% | |
| 9 | Vehicle area, other | 3 | 3.9% | |
| 10 | Bedroom - < 5 persons; included are jail or prison | 2 | 2.6% | |
| 11 | All other areas | 19 | 24.7% |
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 Ayer mix.
| # | Heat source | Count | Share | |
|---|---|---|---|---|
| 1 | Undetermined | 27 | 35.1% | |
| 2 | Heat source: other | 10 | 13.0% | |
| 3 | Arcing | 7 | 9.1% | |
| 4 | Cigarette | 7 | 9.1% | |
| 5 | Heat from powered equipment, other | 5 | 6.5% | |
| 6 | Radiated, conducted heat from operating equipment | 3 | 3.9% | |
| 7 | Chemical reaction | 3 | 3.9% | |
| 8 | Lightning | 3 | 3.9% | |
| 9 | Spark, ember or flame from operating equipment | 2 | 2.6% | |
| 10 | Heat from other open flame or smoking materials | 2 | 2.6% | |
| 11 | All other sources | 8 | 10.4% |
Largest single-incident property losses reported by Ayer departments in 2025. These 7 fires alone account for 100% of the city's annual total.
| # | Property loss | Type | Severity | Status |
|---|---|---|---|---|
| 1 | $200,000 | Building or structure weakened or collapsed | Significant | Investigated |
| 2 | $80,000 | Building fires | Significant | Investigated |
| 3 | $70,000 | Building fires | Significant | Investigated |
| 4 | $50,000 | Mobile property (vehicle) fire, other | Significant | Investigated |
| 5 | $50,000 | Building fires | Significant | Investigated |
| 6 | $2,000 | Building fires | Significant | Investigated |
| 7 | $500 | Electrical wiring/equipment problem, other | Significant | Investigated |
Per-capita rates let us compare apples to apples. Ayer sits above the national average for incidents per resident.
13 fire-related casualties recorded in NFIRS Module 11 across the 2021–2025 window. Age, gender, and severity are coarse-binned — no individual identification possible.
| Age | Count | |
|---|---|---|
| 0-9 | 0 | |
| 10-19 | 0 | |
| 20-29 | 5 | |
| 30-39 | 3 | |
| 40-49 | 2 | |
| 50-59 | 1 | |
| 60-69 | 1 | |
| 70-79 | 1 | |
| 80+ | 0 |
Top 25 wildfires (1992+) in the FPA-FOD ignitions database, scaled by acres. 4,023 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 | 5.7 mi | |
| 2008 | Missing data/not specified/undetermined | 700 | 5.7 mi | |
| 2003 | Missing data/not specified/undetermined | 300 | 27.8 mi | |
| 2002 | Missing data/not specified/undetermined | 300 | 5.7 mi | |
| 2014 | Missing data/not specified/undetermined | 256 | 5.8 mi | |
| 2015 | Missing data/not specified/undetermined | 250 | 5.7 mi | |
| 2016 | Arson/incendiarism | 190 | 42.8 mi | |
| 2007 | Missing data/not specified/undetermined | 186 | 28.3 mi | |
| 2016 | Missing data/not specified/undetermined | 172 | 5.6 mi | |
| 2004 | Missing data/not specified/undetermined | 120 | 32.6 mi | |
| 2014 | Missing data/not specified/undetermined | 90 | 32.2 mi | |
| 2020 | Missing data/not specified/undetermined | 79 | 5.9 mi |
Top 2 ZIP codes by NFIRS incident count across 2021–2025. Each ZIP has its own fire profile — dive in for neighborhood-level context.
Six Massachusetts cities with population within ±25% of Ayer. 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.