In 2025, fire departments serving Mercer Island responded to 88 fire and hazmat incidents — from cooking fires to gas leaks to a single $500K building blaze. Here's the full picture.
Building fires lead by count. Building fires lead by dollars. Together the top five categories make up about 46% of all calls.
Jul peaks. Apr dips. Watch for the typical fall climb starting in October.
434 incidents 2021–2025. Peak year was 2021. $5.8M cumulative property loss.
| Year | Incidents | YoY | |
|---|---|---|---|
| 2021 | 92 | — | |
| 2022 | 77 | -16.3% | |
| 2023 | 86 | +11.7% | |
| 2024 | 91 | +5.8% | |
| 2025 | 88 | -3.3% |
For the 10 building fires Mercer Island departments responded to in 2025, here's how they were classified once investigators were finished.
NFIRS Area of Origin (AREA_ORIG) for the 96 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 | Undetermined | 16 | 16.7% | |
| 2 | Cooking area, kitchen | 14 | 14.6% | |
| 3 | Engine area, running gear, wheel area | 14 | 14.6% | |
| 4 | Other | 8 | 8.3% | |
| 5 | Outside area, other | 7 | 7.3% | |
| 6 | Vehicle storage area; garage, carport | 4 | 4.2% | |
| 7 | Function area, other | 3 | 3.1% | |
| 8 | Highway, parking lot, street: on or near | 3 | 3.1% | |
| 9 | Bedroom - < 5 persons; included are jail or prison | 2 | 2.1% | |
| 10 | Bathroom, checkroom, lavatory, locker room | 2 | 2.1% | |
| 11 | All other areas | 23 | 24.0% |
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 Mercer Island mix.
| # | Heat source | Count | Share | |
|---|---|---|---|---|
| 1 | Undetermined | 45 | 46.9% | |
| 2 | Heat from powered equipment, other | 13 | 13.5% | |
| 3 | Hot or smoldering object, other | 13 | 13.5% | |
| 4 | Arcing | 6 | 6.2% | |
| 5 | Heat source: other | 5 | 5.2% | |
| 6 | Heat from other open flame or smoking materials | 3 | 3.1% | |
| 7 | Cigarette | 3 | 3.1% | |
| 8 | Spark, ember or flame from operating equipment | 1 | 1.0% | |
| 9 | Radiated, conducted heat from operating equipment | 1 | 1.0% | |
| 10 | Molten, hot material | 1 | 1.0% | |
| 11 | All other sources | 5 | 5.2% |
Largest single-incident property losses reported by Mercer Island departments in 2025. These 8 fires alone account for 98% of the city's annual total.
| # | Property loss | Type | Severity | Status |
|---|---|---|---|---|
| 1 | $500,000 | Building fires | Major | Investigated |
| 2 | $350,000 | Building fires | Major | Investigated |
| 3 | $120,000 | Building fires | Significant | Investigated |
| 4 | $100,000 | Building fires | Significant | Investigated |
| 5 | $100,000 | Camper or recreational vehicle (RV) fire | Significant | Investigated |
| 6 | $60,000 | Road freight or transport vehicle fire | Significant | Investigated |
| 7 | $20,000 | Mobile property (vehicle) fire, other | Significant | Investigated |
| 8 | $20,000 | Passenger vehicle fire | Significant | Investigated |
Per-capita rates let us compare apples to apples. Mercer Island sits below the national average for incidents per resident.
Top 25 wildfires (1992+) in the FPA-FOD ignitions database, scaled by acres. 11,548 acres burned in this 50-mile radius. Each dot is a fire — bigger dots burned more land.
| Year | Cause | Acres | Distance | |
|---|---|---|---|---|
| 2018 | Equipment and vehicle use | 3,312 | 41.9 mi | |
| 2011 | Missing data/not specified/undetermined | 1,243 | 41.8 mi | |
| 2017 | Missing data/not specified/undetermined | 1,061 | 46.5 mi | |
| 2009 | Natural | 817 | 44.6 mi | |
| 1997 | Debris and open burning | 594 | 43.4 mi | |
| 2020 | Missing data/not specified/undetermined | 494 | 25.4 mi | |
| 2009 | Natural | 443 | 44.2 mi | |
| 2018 | Natural | 420 | 44.4 mi | |
| 2017 | Missing data/not specified/undetermined | 360 | 30.9 mi | |
| 2003 | Natural | 310 | 49.0 mi | |
| 1999 | Natural | 294 | 41.6 mi | |
| 1995 | Debris and open burning | 290 | 25.6 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 | 98040 | 434 |
Six Washington cities with population within ±25% of Mercer Island. 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.