CalFire Fire Hazard Severity Zone (FHSZ) Screener - CA Parcels

Batch point-in-polygon screening of California coordinates against CAL FIRE's currently adopted Fire Hazard Severity Zone maps - the SRA map dated 2023-09-29 (adopted 2024-01-31, effective 2024-04-01) and the LRA map dated 2025-03-24 - plus a cross-check against the superseded 2007/2011 layers so you can see exactly where the old maps and the operative maps disagree.

Answers, per property: is this parcel in a fire hazard severity zone, which class (Moderate / High / Very High), which jurisdiction (SRA / LRA / federal), and which California Natural Hazard Disclosure boxes are triggered.

What changed in v1.1 (please read if you used v1.0)

v1.0 screened only services.gis.ca.gov/.../Fire_Severity_Zones/MapServer. That service is the superseded vintage - its own layer names say "State Responsibility Areas (2007)" and "Local Responsibility Areas (2011)", and the 2011 layer describes itself as a draft. Measured live on 2026-08-01, against centroids of adopted Very High polygons that were re-verified by point-in-polygon before use:

• 52 of 133 adopted LRA "Very High" points (39.1%) were reported by the old service as clear on all four layers - so v1.0 emitted a billable row reading in_fhsz: false, disclosure_required: false, clear_flag: true on parcels the adopted map classifies Very High. Truckee CA (39.3280, -120.1833) is a reproducible instance.
• 36 of 142 adopted SRA "Very High" points (25.4%) came back at a lower class. Riverside / Woodcrest (33.8600, -117.3900): old map "Moderate", adopted map "Very High".

v1.1 makes the adopted maps authoritative for the headline determination. No field was removed or renamed; every v1.0 answer is preserved verbatim in a parallel *_legacy namespace, and legacy_disagrees_with_current plus legacy_disagreement_detail tell you on every row whether the two map sets differ. Price is unchanged.

Who it's for

• CA real-estate agents & brokers - every California residential transfer needs a Natural Hazard Disclosure statement; nhd_sra_disclosure and nhd_vhfhsz_disclosure answer the two fire boxes per parcel or per portfolio.
• NHD report firms & title companies - pre-screen or cross-check before ordering.
• Insurance underwriters - screen a California book for FHSZ exposure at renewal.
• Home inspectors, appraisers, land developers & lenders - defensible_space_prc4291 and wui_chapter_7a_building_standards flag the construction/maintenance consequences.

What it does

1. Runs live drift assertions before a single billable row exists: the superseded MapServer's four layers must still resolve by name (never by silently falling back to a hardcoded index); each adopted layer must still carry its expected name, polygon geometry and a feature count inside a band (SRA 18,423 / LRA 9,752 as of 2026-08-01); the class vocabulary must be fully decodable and still contain "Very High"; Oakland Hills must still return SRA Very High and Paradise LRA Very High; downtown Sacramento must stay clear on the SRA map while the LRA map still answers it. Any fatal failure ends the run with zero rows and zero billing.
2. Point-in-polygon query per coordinate against both adopted maps and all four legacy layers, with outSR=4326 and a geometry check that verifies WGS84 by declared spatial reference, coordinate magnitude and each feature's own extent.
3. If the coordinate is clear of every hazard polygon, an optional radius search for the nearest mapped zone, paged explicitly and reconciled against the service's own exact record count (returnCountOnly) so truncation cannot pass silently.
4. Classifies: verdict, in_hazard_severity_zone, hazard_class_current, responsibility_area_current, and the two statutory disclosure flags - with a written disclosure_basis audit trail naming what each map returned and the rule applied.

Failure behaviour (what "no result" means)

• Every source records its own outcome on every row (sra23_status, lra25_status, legacy_*_status, sources_ok_count, sources_failed, partial_result).
• null means not checked; false means checked and negative. A source that did not answer can never produce a confident negative - the row reads verdict: indeterminate and the note says so explicitly.
• A positive finding is trusted from any source that answered; a negative requires every contributing source to have answered.
• If every asset fails, the run fails and bills nothing rather than selling one error row per asset. The gate runs before pushData, not after.
• Missing assets is rejected by the input schema (HTTP 400, before the run starts).

Example input

{
  "assets": [
    { "lat": 37.8555, "lon": -122.2100, "label": "Oakland Hills CA - SRA Very High" },
    { "lat": 39.7596, "lon": -121.6219, "label": "Paradise CA - LRA Very High" },
    { "lat": 39.3280, "lon": -120.1833, "label": "Truckee CA - Very High only on the 2025 adopted map" },
    { "lat": 38.5820, "lon": -121.4940, "label": "Downtown Sacramento CA - clear control" }
  ],
  "checkNearby": true,
  "nearbyRadiusMiles": 0.5
}

Output fields (one row per screened asset - all 74 fields)

Every field below is nullable. A null means not checked; false means checked and negative.

Field	Type	Description
asset_label	string / null	Caller-supplied label for the screened site.
asset_lat	number / null	WGS84 latitude of the screened site.
asset_lon	number / null	WGS84 longitude of the screened site.
in_fhsz	boolean / null	TRUE if the coordinate falls inside one or more mapped CAL FIRE Fire Hazard Severity Zone polygons (SRA, LRA, pending, or federal). Null on error rows.
hazard_class	string / null	Hazard class of the primary matched zone: Moderate, High, or Very High. Null if no hit or the class attribute could not be resolved.
responsibility_area	string / null	Fire responsibility jurisdiction of the primary matched zone: SRA (State Responsibility Area), LRA (Local Responsibility Area), or Federal.
zone_status	string / null	'adopted' for a formally adopted SRA/LRA/federal FHSZ zone, or 'pending' for a CAL FIRE-recommended zone not yet locally adopted. Null if no hit.
disclosure_required	boolean / null	TRUE when the site falls within an adopted SRA zone of any hazard class, or an adopted LRA Very High zone — the California Natural Hazard Disclosure trigger under Civ. Code Section 1103.7 / Gov. Code Section 51178. FALSE for pending/federal-only hits or a clear site. Null on error rows.
layers_matched	string / null	Semicolon-separated list of every FHSZ layer whose polygon contains this exact coordinate (can be more than one where zones overlap).
nearby_zone_within_radius	boolean / null	TRUE if the exact coordinate is clear but a mapped FHSZ falls within the search radius (near-boundary flag). Always false when in_fhsz is true.
nearby_hazard_class	string / null	Hazard class of the nearest zone found within the search radius when the exact coordinate itself is clear.
nearby_distance_miles	number / null	Approximate distance in miles (nearest-polygon-vertex proxy) to the nearest mapped zone when the exact coordinate itself is clear.
layer_source	string / null	MapServer query URL for the layer of the primary hit (or the base service URL when no hit).
clear_flag	boolean / null	TRUE if the site is outside every mapped FHSZ layer and outside the nearby search radius (or outside California coverage entirely). Null on error rows.
note	string / null	Plain-English summary of the result for this asset, including the disclosure-law citation when applicable.
error	string / null	Per-asset error message (invalid coordinate or query failure); null when OK.
disclaimer	string / null	Informational-screen / not-a-substitute-for-an-NHD-report note.
source_url	string / null	CAL FIRE FHSZ MapServer used.
checked_at	string / null	ISO 8601 timestamp of the run.
determination_source	string / null	Which map set produced the headline determination: "adopted-2023-2025" (both currently adopted CAL FIRE maps answered), "adopted-partial" (only one answered) or "legacy-only" (neither adopted map answered).
current_map_vintage	string / null	Vintage of the currently adopted CAL FIRE maps this actor screens against.
in_hazard_severity_zone	boolean / null	TRUE when the coordinate falls inside a Moderate, High or Very High polygon on a CURRENTLY ADOPTED CAL FIRE map. Excludes LRA NonWildland polygons (mapped, but explicitly not hazard zones) and federal responsibility-area polygons (no hazard class). NULL when an adopted map did not answer.
hazard_class_current	string / null	Hazard class from the currently adopted maps: Moderate, High, Very High, or NonWildland. NULL when no adopted polygon covers the coordinate or the source did not answer.
hazard_class_code_current	number / null	CAL FIRE numeric FHSZ code behind hazard_class_current: 1 Moderate, 2 High, 3 Very High, -3 NonWildland.
responsibility_area_current	string / null	SRA or LRA, from whichever currently adopted map produced the primary hit.
sra_fhsz_class	string / null	Hazard class from the adopted State Responsibility Area map (dated 2023-09-29, effective 2024-04-01). NULL if the coordinate is not in SRA.
lra_fhsz_class	string / null	Hazard class from the adopted Local Responsibility Area map (dated 2025-03-24), which publishes Moderate, High, Very High AND NonWildland. NULL if the coordinate is not in LRA.
in_state_responsibility_area	boolean / null	TRUE when the coordinate is inside the adopted SRA FHSZ map. Being in SRA at all is the Civ. Code 1103.2(a)(3) disclosure trigger. NULL when the SRA source did not answer.
in_local_responsibility_area	boolean / null	TRUE when the coordinate is inside any polygon of the adopted LRA FHSZ map, including a NonWildland polygon. NULL when the LRA source did not answer.
in_federal_responsibility_area	boolean / null	TRUE when the coordinate is inside a Federal Responsibility Area jurisdiction polygon (federal land). FRA polygons carry no hazard class and are not a California disclosure trigger. NULL when that layer did not answer.
sra_map_dated	string / null	Date of the adopted SRA FHSZ map that answered this row.
sra_map_adopted	string / null	Date the SRA FHSZ map was formally adopted by the State Fire Marshal.
sra_map_effective	string / null	Date the SRA FHSZ map took legal effect.
lra_map_dated	string / null	Date of the adopted LRA FHSZ map that answered this row.
nhd_sra_disclosure	boolean / null	TRUE when the Natural Hazard Disclosure statement "State Fire Responsibility Area" box (Civ. Code 1103.2(a)(3)) is triggered. Informational; confirm with a licensed NHD provider. NULL when not checked.
nhd_vhfhsz_disclosure	boolean / null	TRUE when the "Very High Fire Hazard Severity Zone" box (Civ. Code 1103.2(a)(2) / Gov. Code 51178) is triggered - a Very High class in SRA or LRA. Informational. NULL when not checked.
defensible_space_prc4291	boolean / null	TRUE when PRC 4291 100-foot defensible-space obligations likely apply (SRA of any class, or a Very High zone). Informational, not a legal determination. NULL when not checked.
wui_chapter_7a_building_standards	boolean / null	TRUE when CBC Chapter 7A / CRC R337 wildland-urban-interface construction standards likely apply to new construction (SRA of any class, or a Very High zone). Informational. NULL when not checked.
disclosure_basis	string / null	Audit trail for the disclosure determination: what each adopted map returned at this coordinate, and the rule applied.
in_fhsz_legacy	boolean / null	What v1.0 of this actor answered for in_fhsz, computed only from the superseded CAL FIRE SRA-2007 / LRA-2011 MapServer layers. Preserved for continuity and back-comparison. NULL when those layers did not answer.
hazard_class_legacy	string / null	Hazard class from the superseded 2007/2011 layers.
responsibility_area_legacy	string / null	Responsibility area from the superseded 2007/2011 layers.
zone_status_legacy	string / null	adopted or pending, from the superseded 2007/2011 layers.
disclosure_required_legacy	boolean / null	The v1.0 disclosure determination, computed only from the superseded 2007/2011 layers, so a caller can see exactly what changed. NULL when those layers did not answer.
layers_matched_legacy	string / null	Superseded MapServer layers whose polygon contains this coordinate.
legacy_map_vintage	string / null	Vintage of the superseded CAL FIRE layers used for the cross-check.
legacy_disagrees_with_current	boolean / null	TRUE when the superseded 2007/2011 layers would have produced a different disclosure flag or hazard class than the currently adopted maps. NULL when either map set did not answer.
legacy_disagreement_detail	string / null	How the superseded and adopted maps differ at this coordinate.
pending_zoning_hit	boolean / null	TRUE when the coordinate falls in the superseded service SRA/LRA Awaiting Zoning layer. Informational only. NULL when that layer did not answer.
pending_zoning_class	string / null	Hazard class recorded on the pending/awaiting-zoning polygon where one is published (82% of that layer carries a blank class).
sra23_status	string / null	ok when the adopted SRA map answered for this coordinate, unavailable when it did not. Any derived negative is NULL rather than false while this is unavailable.
lra25_status	string / null	ok when the adopted LRA map answered for this coordinate, unavailable when it did not.
legacy_sra_status	string / null	ok / unavailable for the superseded SRA-2007 layer.
legacy_lra_status	string / null	ok / unavailable for the superseded LRA-2011 layer.
legacy_pending_status	string / null	ok / unavailable for the superseded SRA/LRA Awaiting Zoning layer.
legacy_federal_status	string / null	ok / unavailable for the Federal Responsibility Areas layer.
sources_ok_count	number / null	How many of the six contributing sources answered for this coordinate.
sources_total_count	number / null	Total contributing sources (2 adopted maps + 4 superseded legacy layers).
sources_failed	string / null	Comma-separated list of sources that did not answer for this coordinate; null when all six answered.
partial_result	boolean / null	TRUE when at least one contributing source did not answer, so some fields on this row are NULL (not checked) rather than a verified negative.
nearby_checked	boolean / null	TRUE when the near-boundary radius search actually ran. FALSE when it was skipped because the coordinate is already inside a zone, or checkNearby was off. When false, nearby_zone_within_radius is NULL, never false.
nearby_source	string / null	Which layer produced the nearest mapped zone: sra23, lra25, or a legacy_* layer.
nearby_responsibility_area	string / null	Responsibility area of the nearest mapped zone within the radius.
nearby_zone_status	string / null	adopted or pending, for the nearest mapped zone within the radius.
near_boundary_band	string / null	Banded distance to the nearest mapped zone: inside_zone, within_0.1_mi, within_0.25_mi, within_0.5_mi, within_1_mi, within_5_mi, beyond_5_mi. NULL when the radius search did not run.
nearby_truncated	boolean / null	TRUE when a radius query hit the service transfer limit, so the nearest-zone answer may be computed over an incomplete set. NULL when no radius query ran.
truncation_guard	string / null	ok when every paged query returned the service own exact record count, truncated when a transfer limit was hit, not_applicable when no paged query ran.
geometry_sr_check	string / null	ok when returned geometry was verified as WGS84 by declared spatial reference, coordinate magnitude and per-feature extent; a failure reason otherwise.
out_of_california_coverage	boolean / null	TRUE when the coordinate is outside the CAL FIRE FHSZ program area, so no zone determination applies.
verdict	string / null	Headline verdict: disclosure_required, mapped_no_disclosure, near_boundary, clear, clear_current_maps, indeterminate, out_of_coverage, or error. Never reads clear while a contributing source is unavailable.
verdict_basis	string / null	Why the verdict is what it is, naming the map and rule applied or the sources that failed.
drift_checks_passed	number / null	How many live upstream drift assertions passed before any row was emitted. A fatal drift failure ends the run with zero rows and zero billing.
fhsz_service_layer_ids	string / null	role=layerId map resolved at runtime from the superseded MapServer layer list.
current_zone_object_id	number / null	OBJECTID of the adopted CAL FIRE polygon that produced the primary hit, so the exact zone can be re-opened in the CAL FIRE FHSZ viewer or re-queried from the source FeatureServer.

Use as an MCP tool

This actor is Pay-Per-Event (Result-only) and discoverable via mcp.apify.com - an AI agent (Claude, Cursor, etc.) can call it directly as a chainable tool: pass an array of {lat, lon, label} assets and get back a structured disclosure determination per site. Because unavailable sources are reported as null rather than false, an agent can tell "verified clear" apart from "could not check" without reading the log.

FAQ

Is my house in a fire hazard severity zone? Pass its coordinates; verdict, in_hazard_severity_zone and hazard_class_current answer directly, against the maps that are legally in effect today.

Which map does this use? The adopted SRA map dated 2023-09-29 (effective 2024-04-01) and the adopted LRA map dated 2025-03-24. sra_map_dated / sra_map_effective / lra_map_dated are stamped on every row. The superseded 2007/2011 layers are still queried, but only to populate the *_legacy cross-check fields.

My old FHSZ lookup said something different. Check legacy_disagrees_with_current and legacy_disagreement_detail. Roughly 39% of adopted LRA Very High locations read as completely clear on the 2011 draft layer, and CAL FIRE both up- and down-classified parcels in the 2023/2025 revisions.

Natural hazard disclosure - do I have to disclose this on a home sale? nhd_sra_disclosure covers the "State Fire Responsibility Area" box (Civ. Code 1103.2(a)(3), triggered by SRA status of any class) and nhd_vhfhsz_disclosure covers the "Very High Fire Hazard Severity Zone" box (Civ. Code 1103.2(a)(2) / Gov. Code 51178, triggered by a Very High class in SRA or LRA). These are informational screening flags - always confirm with a licensed NHD provider before closing.

What is "NonWildland"? The adopted 2025 LRA map publishes 1,954 NonWildland polygons (20.0% of the layer) covering most urban California - downtown Sacramento sits in one. They are mapped, but they are explicitly not hazard zones, so they never set in_hazard_severity_zone or any disclosure flag. lra_fhsz_class still reports them so you can see the coordinate was genuinely covered rather than missed.

What's the difference between SRA, LRA and FRA? SRA = State Responsibility Area (CAL FIRE jurisdiction; being in it at all triggers the SRA disclosure box). LRA = Local Responsibility Area (the 2025 map publishes Moderate, High and Very High; only Very High triggers the Gov. Code 51178 box). FRA = Federal Responsibility Area, a land-ownership boundary that carries no hazard class and triggers nothing - reported as in_federal_responsibility_area only.

Can a clear result be wrong? A clear verdict is only emitted when all six sources answered. If any did not, you get indeterminate and sources_failed, never a false clear. A clear still does not rule out local WUI ordinances, defensible-space law or an insurer's own wildfire model.

Related actors

• wildfire-asset-exposure-screener - active perimeters, Wildfire Hazard Potential class and historical burn footprint for the same coordinates.
• fema-nri-county-risk-profile - FEMA National Risk Index wildfire and multi-peril scores at county and census-tract resolution.
• usgs-landslide-proximity-screener - post-fire debris-flow context for burn-scar sites.
• site-due-diligence-bundle - 20-layer federated screen (this FHSZ check included) with a composite site score and go / caution / no-go verdict.

Source & disclaimer

Data: CAL FIRE / Office of the State Fire Marshal FHSZ FeatureServers (services1.arcgis.com/jUJYIo9tSA7EHvfZ) and the CA Government Operations Agency FHSZ MapServer (services.gis.ca.gov). Keyless public services, no API key required. This is an informational screening tool, not a substitute for the official CAL FIRE FHSZ viewer or a licensed Natural Hazard Disclosure report. Zone boundaries are periodically revised - confirm current adopted status with the local fire authority or an NHD provider before any real-estate, insurance or construction decision.

Pricing: $8 per 1,000 result rows (Pay-Per-Event, Result-event only), with graduated paid-plan discounts. One row per asset, including clear sites. Categories: Real estate, Developer tools, Agents.