---
title: "Uhi Features"
method: GET
path: "/api/tools/uhi/features"
tags: ["Tools (analyse and convert EPW files)"]
---

# Uhi Features

`GET /api/tools/uhi/features`

## Request

- Base URL: `https://epw.tools`
- URL: `https://epw.tools/api/tools/uhi/features`
- Auth: none declared

Compute site features (NLCD + OSM + dist_km) and return UHI prediction.

Fetches NLCD 2021 tree canopy and impervious surface from MRLC WCS,
OSM building morphology (lambda_p, H_mean_m) via the OSM REST API, and
computes distance to the nearest major US city centre.  The response
includes both the raw features and the predicted UHI delta temperatures
(same payload as /api/tools/uhi/predict).

This call may take 5-15 seconds due to upstream WCS + OSM requests, so it
is rate-limited (R6-1): each request fans out to three external services,
so leaving it open would let anyone use us to hammer OSM/MRLC and exhaust
the executor. Results are cached per coordinate (R6-2), so repeat lookups
do not touch the upstreams. Anonymous preview stays available but is
limited per-IP; an authenticated key gets the higher per-key limit.

## Query parameters

- `lat` number, required: Latitude
- `lon` number, required: Longitude

## Headers

- `X-API-Key` string, nullable

## Response `200`

Successful Response

- unknown

## Other responses

- `422`: Validation Error

---

[API](https://skmtc.dev/epw/apis/epw-tools-api.md) · [All operations](https://skmtc.dev/epw/apis/epw-tools-api/llms.txt) · [OpenAPI document](https://skmtc.dev/epw/apis/epw-tools-api/revisions/e6b60fc7a6d7?raw)