Data sources & methodology
A wildfire map is only as trustworthy as the feeds behind it. Plenty of sites re-blend the same scraped data without ever saying where a number came from, how old it is, or where it stops being reliable.
When the subject is fire and smoke near where people live, “trust us” is not good enough — a stale or invented figure can push someone the wrong way on a day that matters.
So every number on this site traces to a primary government feed, carries its own “data as of” timestamp, and states its own limits. This page is that ledger: what each feed is, who runs it, how fresh it is, what we use it for, and where its reliability ends.
How we source, in five rules
The same discipline runs through every page. It is deliberately boring, and that is the point — boring is what “every number sourced” actually looks like.
- Primary sources only. Data comes from the agency that produces it — NIFC, NASA, NOAA, EPA — never from a competitor's scraped aggregation.
- Honest about gaps. Missing data is disclosed, never invented. A monitor that isn't reporting shows “no data,” not zero; a map gap means no coverage there, not clean air.
- Computed is labelled computed. Anything we add up or derive — a multi-year total, a per-state count — is marked as our calculation, distinct from what the agency published.
- Preliminary is labelled preliminary. Where a feed says its data isn't fully verified (AirNow) or is an analyst estimate (HMS), we relay that caveat verbatim rather than laundering it into a clean-looking number.
- Availability is separate from recency. The live feed-health strip below tracks whether a source is reachable right now — a different thing from how fresh its last-good data is.
Live feed health
Availability probed live — tracked separately from data recency.
The primary feeds, one by one
Six sources do the work. Each entry says what the dataset is, who runs it, how often it refreshes, which pages here it powers, where it stops being reliable, and how it's licensed and attributed — all straight from the source registry below.
NIFC WFIGS — the fire system of record
WFIGS (Wildland Fire Interagency Geospatial Services) is the United States' interagency system of record for wildfire incidents: a point location for every reported incident, plus perimeter polygons for the larger ones. Each incident carries dozens of fields — name, size, percent contained, state of origin, discovery time, incident type. It is run by NIFC, the National Interagency Fire Center, and published through its open ArcGIS services.
- Cadence:
- continuous, under documented fall-off rules.
- What we use it for:
- the incident points and perimeters behind the live national wildfire map and every state fire map (filtered per state).
- Limits & caveats:
- perimeters are a subset — not every incident has a mapped polygon — and percent-contained can be blank. A fire is never marked “extinguished”: under the fall-off rules it transitions to a historical state and persists as a dated record.
- License & attribution:
- US government public domain; relayed as “Source: NIFC WFIGS — retrieved [date].”
NASA FIRMS — satellite heat detections
FIRMS (Fire Information for Resource Management System) reports near-real-time thermal anomalies from satellite sensors — MODIS, VIIRS, and Landsat — each with a confidence value, fire radiative power, and a day/night flag. It is run by NASA. Crucially, a FIRMS record is a satellite heat signature, not a confirmed fire and not a photograph.
- Cadence:
- ultra-real-time over the US and Canada — detections arrive in under ~60 seconds of the satellite overpass.
- What we use it for:
- the heat-detection layer on the national wildfire map and the wildfire smoke map, alongside the smoke plumes.
- Limits & caveats:
- a detection is a heat signal, so we label it a detection, not a confirmed fire; a non-wildfire heat source can trip it. Near-real-time coverage here is US + Canada.
- License & attribution:
- US government public domain (access via a NASA map key); relayed as “Source: NASA FIRMS — retrieved [date].”
NOAA HMS — smoke, drawn by an analyst
The Hazard Mapping System (HMS) smoke product is exactly what it sounds like: NOAA analysts look at satellite imagery and hand-draw the outline of visible smoke once a day, grading each plume Light, Medium, or Heavy. It is produced by NOAA OSPO (Office of Satellite and Product Operations). It is an analysis of the atmospheric column, not a ground sensor.
- Cadence:
- a once-a-day, dated analyst product; today's file can be an empty stub until it's finalized, and there is no backfill.
- What we use it for:
- the grey smoke plumes on the wildfire smoke map and the smoke layer on the home map.
- Limits & caveats:
- it maps column smoke, not ground level — a grey plume overhead can sit above clean air you breathe; clouds can hide smoke. It is a CONUS+ national product — reaching beyond the contiguous US — while our fire layers are US-only, so heavy smoke with no fire dots beneath it can be drifting in from outside our fire coverage: scope, not a bug.
- License & attribution:
- US government public domain; relayed as “Source: NOAA OSPO HMS — retrieved [date].”
EPA AirNow — observed air quality
AirNow is the observational air-quality network run by the EPA together with state, local, and tribal air agencies. It reports ground-monitor fine-particle (PM2.5) readings as an AQI, with the site name and reporting agency attached to each point.
- Cadence:
- hourly, published roughly 10–30 minutes past the hour.
- What we use it for:
- the monitor map and the by-location or ZIP reading, plus the multi-day AirNow forecast, on the air quality map.
- Limits & caveats:
- readings are preliminary and not fully verified — a license condition is that they are not for regulatory use. Coverage isn't uniform, so a gap on the map is missing coverage, not clean air.
- License & attribution:
- free with an account, under AirNow's data-exchange guidelines; the required wording — “Preliminary data not fully verified — EPA AirNow and reporting agencies” — is contractual and relayed verbatim on the page.
NICC / NIFC — annual fire statistics
For the long view, we relay the national annual wildland-fire totals — total fires and total acres burned each year from 1983 through 2025 — compiled by the National Interagency Coordination Center (NICC). The 1983–2021 figures come from the NICC Situation Report table; 2022–2025 come from the NICC 2025 Annual Report's national total row (the overlap year, 2021, matches across both).
- Cadence:
- annual, with year-to-date figures during the season.
- What we use it for:
- the charts and records on US wildfire statistics, and the historical context on the 2026 season tracker.
- Limits & caveats:
- per NIFC, figures before 1983 are not comparable, so we don't show them. Any multi-year sum we compute is labelled as our calculation; where the 2025 report's prose conflicts with its own agency-summed total for 2024, we use the total row. This is not an official government service.
- License & attribution:
- US government public domain; relayed as “Source: National Interagency Coordination Center (NICC) / NIFC.”
Natural Earth — the cartographic basemaps
The outlines under the data — US state boundaries (50 states + DC), city labels, major highways, lakes, and rivers — are vendored from Natural Earth, a public-domain cartographic dataset. Coordinates are rounded and simplified for size, and each file is pinned by checksum.
- Cadence:
- static — a fixed Natural Earth release, re-vendored only when we refresh it.
- What we use it for:
- map orientation — the outlines, labels, and water features that give the fire and smoke data geographic context on the national and state maps.
- Limits & caveats:
- cartographic only — this is geometry for orientation, never a cited-number source, and the coordinates are deliberately simplified.
- License & attribution:
- public domain under Natural Earth's terms (commercial use fine, no permission needed). The interactive vector basemap tiles come from OpenStreetMap via OpenFreeMap, credited “© OpenStreetMap contributors · OpenFreeMap” on the map.
Data & methodology FAQ
- Where does US Wildfire Map get its data?
- From the agencies that produce it: NIFC WFIGS for fire incidents and perimeters, NASA FIRMS for satellite heat detections, NOAA HMS for smoke, and EPA AirNow for air quality, plus NICC for annual statistics and Natural Earth for basemaps. Nothing is scraped from another map site — the full list, with licenses, is in the registry below.
- Is the data official and real-time?
- The sources are official government feeds, but this site is not an official government service. Freshness varies by feed: WFIGS updates continuously, FIRMS detections land within a minute of a satellite pass, AirNow is hourly, and HMS smoke is a once-a-day analyst product. Each figure shows its own “data as of” time.
- Why don't the fire detections and the smoke line up?
- Three reasons: smoke travels hundreds of miles downwind of its fire; NOAA HMS covers more than the contiguous US (a CONUS+ product) while our fire layers are US-only; and the two run on different clocks (daily smoke vs. continuous detections). It's data scope, not an error — more on the wildfire smoke map.
- What does “preliminary” mean for the air-quality data?
- AirNow observations are published fast and flagged by the EPA as preliminary and not fully verified — a license condition is that they aren't for regulatory use. We relay that wording rather than presenting the numbers as final.
- How do I know a number here wasn't made up?
- Every figure ties to a feed in the registry, carries a timestamp, and comes with an epistemic label saying what it is not (a detection isn't a confirmed fire; column smoke isn't a ground reading). Anything we compute is labelled computed, and missing data is shown as missing — see about this project for who builds and reviews it.
Full source registry
The complete, machine-checkable list — every feed above plus the cartographic layers and the candidate sources not yet built on — generated straight from our source registry. The epistemic label is each source's honest caveat.
| Source | Operator | Cadence | License | Status |
|---|---|---|---|---|
| WFIGS incident locations + perimetersfall-off transitions pages to historical state — never "extinguished" | NIFC | continuous (documented fall-off rules) | US gov public domain | verified |
| FIRMS active fire detections (MODIS+VIIRS+Landsat NRT)label: satellite heat detections not confirmed fires | NASA | US/Canada ultra-real-time (<60s from flyover) | US gov public domain | verified |
| Hazard Mapping System smoke polygonslabel: atmospheric column smoke daily analysis | NOAA OSPO | daily analyst product | US gov public domain | verified |
| AirNow observational AQImandatory attribution wording is contractual not editorial; forecast/latLong + observation/{latLong,zipCode}/current verified 2026-08-12 (same host + AIRNOW_API_KEY) | EPA + state/local/tribal agencies | hourly (10-30 min past hour) | free with account; data-exchange guidelines are a license condition | verified |
| HRRR-Smoke forecast (near-surface + column smoke)experimental model output — attribute as forecast not observation; Phase-2 raw-model integration; v1 relays NOAA graphics + AirNow forecast | NOAA (GSL/EMC) | hourly model runs | US gov public domain | verified |
| Wildfire smoke & PM2.5 health effects (relay-only)YMYL — MPharm real-name byline + reviewed date; relay agency guidance ONLY per CREDIBILITY RULE; every claim attributed to its EPA source | US EPA | stable reference | US gov public domain | verified |
| US state boundaries (admin-1 outlines)cartographic basemap only (geometry used for map orientation); not a cited-number source | Natural Earth | static (Natural Earth 1:50m release) | public domain (Natural Earth terms — no permission needed; commercial use OK) | verified |
| NIFC/NICC wildfire statistics (annual total fires + acres 1983-2025; largest fires)pre-1983 not comparable per NIFC; 2022-2025 use the agency-summed Total row (structured), not the report prose which mis-states 2024 fires; computed sums labeled; not an official government service | NICC / NIFC | annual + YTD | US gov public domain | verified |
| US city labels (populated places)cartographic city labels only (map orientation context); not a cited-number source | Natural Earth | static (Natural Earth 1:10m release) | public domain (Natural Earth terms — no permission needed; commercial use OK) | verified |
| Interactive basemap vector tiles (OpenStreetMap via OpenFreeMap)keyless hosted OpenFreeMap; Positron re-tinted to map.* tokens (desaturated <= --muted); OpenMapTiles schema; DEPENDENCY third-party host; FALLBACK chooseBasemap -> GeoJSON basemap -> self-contained real-map floor (unit-tested); NEXT_PUBLIC_PMTILES_URL still overrides to self-hosted Protomaps PMTiles when set | OpenFreeMap / OpenStreetMap | live hosted (OpenFreeMap refreshes the planet periodically) | ODbL (OpenStreetMap data) — attribution required; OpenFreeMap free incl. commercial | verified |
| US major highways (interstate + US-highway skeleton)cartographic basemap only (map orientation context); not a cited-number source | Natural Earth | static (Natural Earth 1:10m release) | public domain (Natural Earth terms — no permission needed; commercial use OK) | verified |
| US lakes (major named lakes + reservoirs)cartographic basemap only (map orientation context); not a cited-number source | Natural Earth | static (Natural Earth 1:10m release) | public domain (Natural Earth terms — no permission needed; commercial use OK) | verified |
| US rivers (major river centerlines)cartographic basemap only (map orientation context); not a cited-number source | Natural Earth | static (Natural Earth 1:10m release) | public domain (Natural Earth terms — no permission needed; commercial use OK) | verified |
| EPA Guide to Air Cleaners in the Home (portable air cleaner CADR sizing)sizing METHODOLOGY only; named products DEFERRED (purifier-specs stays candidate until per-product CADR verified chat-side); no affiliate links until FTC disclosure + verification | US EPA | stable reference | US gov public domain | verified |
| EPA research on DIY air cleaners to reduce wildfire smoke indoorsDIY build guide relays EPA specs; fan-safety (post-2012 UL/ETL) stated; CADR findings attributed; no product links | US EPA | stable reference | US gov public domain | verified |
| NICC 2025 Wildland Fire Annual Report (national totals + agency/geographic breakdowns)supplementary primary for the 2022-2025 extension; cite only what the page uses | NICC / NIFC | annual | US gov public domain | verified |
| NWS alerts (red flag warnings)phase 2 layer | NOAA NWS | continuous | US gov public domain | candidate |
| SPC fire weather outlooksphase 2 layer | NOAA SPC | daily | US gov public domain | candidate |
| Open-Meteo windcommercial-use terms must be cleared first | Open-Meteo | hourly | free non-commercial tier — VERIFY commercial terms | candidate |
| Published manufacturer CADR/spec sheetsvisible "spec comparison not lab-tested" methodology line required | manufacturers (per unit) | static per model | manufacturer-published specs; cite per unit | candidate |
| Basemap vector tiles (Protomaps daily build of OpenStreetMap)self-hosted PMTiles basemap re-tinted to tokens; env NEXT_PUBLIC_PMTILES_URL (=/tiles/us.pmtiles dev; Blob URL prod); extract: pmtiles extract https://build.protomaps.com/YYYYMMDD.pmtiles public/tiles/us.pmtiles --bbox=-179.15,18.91,-66.94,71.39 --maxzoom=13; produced-file sha256 TO-BE-FILLED-BY-MARKO; glyphs env NEXT_PUBLIC_GLYPHS_URL (self-host at Phase H) | Protomaps / OpenStreetMap | static (periodic re-extract from the Protomaps daily build) | ODbL (OpenStreetMap data) — attribution required; Protomaps schema/style BSD | candidate |
Candidate sources are disclosed but never built on until verified. Cadence and license are the registry's own fields; “verified” means a spike confirmed the endpoint, fields, and license.
Method & review
Each feed above is read from its primary source and attributed on the page with a retrieval timestamp. A serve-stale cache keeps the last-good reading during an outage — with a banner and its stamp — so a hiccup never renders as a fake zero. Availability is probed live and shown in the feed-health strip, separate from data recency. Reviewed by Marko Visic, BSc Physics. Not an official government service — informational only.