---
title: "FEMA National Risk Index for a US county - the..."
method: GET
path: "/api/gov/risk-index"
tags: ["gov"]
---

# FEMA National Risk Index for a US county - the...

`GET /api/gov/risk-index`

## Request

- Base URL: `https://2s.io`
- URL: `https://2s.io/api/gov/risk-index`
- Auth: API key in header `PAYMENT-SIGNATURE`

FEMA National Risk Index for a US county — the authoritative natural-hazard risk profile. Look up by countyFips (5-digit STCOFIPS), by state + county name, or by a lat/lon point. Returns the composite Risk Index score/rating/national-percentile (an 18-hazard model combining Expected Annual Loss × Social Vulnerability ÷ Community Resilience), each component (expected annual loss in dollars, social vulnerability, community resilience) with its rating, and per-hazard risk ratings + expected-annual-loss for all 18 natural hazards (wildfire, earthquake, hurricane, riverine & coastal flooding, tornado, heat/cold wave, drought, etc.). The structural natural-hazard risk picture an LLM can't recall — for siting, insurance, and resilience planning. Free, public-domain. Complements geo.flood-zone (which is flood SFHA only).

## Query parameters

- `countyFips` string
- `state` string
- `county` string
- `lat` number
- `lon` number
- `trial` 1

## Other responses

- `200` (unresolved $ref)
- `400`: Invalid request — not charged. error.code: BAD_REQUEST or INVALID_PARAM (parameter validation; error.details.issues lists each problem), MALFORMED_JSON, or a request-specific code. Other client errors: 405 METHOD_NOT_ALLOWED (wrong verb; see the Allow header), 413 PAYLOAD_TOO_LARGE.
- `402`: Payment required. Body is the x402 PaymentRequirements envelope with a multi-network accepts array; the per-call price is in accepts[].amount (and on the operation as x-2s-price). Sign for whichever rail you hold USDC on (EIP-3009 for Base, partial SPL transfer for Solana) and retry with the PAYMENT-SIGNATURE header (X-PAYMENT also accepted for v1 clients). Also PAYMENT_SETTLE_FAILED (error envelope) when a verified payment failed to settle: error.details.chargeStatus is "not_charged" (retry with a fresh payment) or "unknown" (the authorization may still settle before its deadline — check it before retrying).
- `429`: Too many requests — RATE_LIMITED: our per-IP / per-payer limiter. Not charged; retry after Retry-After.
- `5XX`: Server-side failure. 500 INTERNAL: unexpected error; quote error.errorId (also the X-2s-Error-Id header). 502 UPSTREAM_UNAVAILABLE (or another UPSTREAM_* code): the data provider failed — composite endpoints refuse unbilled when every source fails. 503 SERVICE_PAUSED: endpoint paused by the operator kill switch, retry after Retry-After; 503 SPEND_CAP: daily upstream budget exhausted. 504 UPSTREAM_TIMEOUT. Not charged.

---

[API](https://skmtc.dev/2s-io/apis/2s-the-most-everything-api.md) · [All operations](https://skmtc.dev/2s-io/apis/2s-the-most-everything-api/llms.txt) · [OpenAPI document](https://skmtc.dev/2s-io/apis/2s-the-most-everything-api/revisions/da4c5caf686e?raw)