---
title: "Design summer year (overheating)"
method: POST
path: "/api/generate/dsy"
tags: ["Generate weather files"]
---

# Design summer year (overheating)

`POST /api/generate/dsy`

## Request

- Base URL: `https://epw.tools`
- URL: `https://epw.tools/api/generate/dsy`
- Auth: API key in header `X-API-Key`

UK Design Summer Year (CIBSE TM49 / Eames-2016 methodology) — 3 real,
continuous years (DSY1/DSY2/DSY3), not a CIBSE-branded reproduction (see
build_dsy_epw() docstring in methods.py for the honesty caveat).

## Headers

- `X-API-Key` string, nullable

## Request body

- DSYRequest: UK Design Summer Year — 3 real, continuous years (not a month-blend like TMY/XMY) selected via the published CIBSE TM49 / Eames(2016) methodology. See select_dsy_years()/build_dsy_epw() in methods.py.
  - `lat` number, required
  - `lon` number, required
  - `location_name` string, required
  - `start_year` integer, required
  - `end_year` integer, required
  - `dc_edition` string
  - `data_source` string

## Response `200`

Successful Response

- unknown

## Other responses

- `402`: Insufficient credits for this operation.
- `422`: Validation Error
- `429`: Rate limit exceeded — retry after a short delay.

---

[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)