> For the complete documentation index, see [llms.txt](https://doc.duaer.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://doc.duaer.com/getting-started/weather-history.md).

# Weather history in Duaer

In Duaer: Past weather back to 1940 for any place: daily or monthly mean, high, low, and rainfall from the Open-Meteo reanalysis archive. One successful search uses 1 credit.
## What you get

Duaer Weather history returns past daily or monthly weather for a place from the Open-Meteo historical archive (ERA5 reanalysis). Use step=month to fold a year or more into twelve readable rows.

Pick Duaer Data → Weather history in the node creator, or open the [data market](/getting-started/data-market.md). Related: [Weather forecast](/getting-started/weather.md), [River flow](/getting-started/river-flow.md).

## When to use it

- Compare a season or a month with past years, or explain a sales or yield change by weather.
- Build a monthly climate table for a site before a visit, a harvest, or a construction plan.

## When not to use it

- The next days. Use [Weather forecast](/getting-started/weather.md).
- Recent days: the archive lags about five days behind today.

## Search on the canvas

1. Open the node creator and pick Duaer Data → Weather history.
2. Fill Place (such as Beijing), From (such as 2024-01-01), To (such as 2024-12-31). Optional: Latitude, Longitude, Step.
3. Limit defaults to 10, max 20. Execute.

A search uses 1 credit only when it returns rows. No rows, wrong input, or an upstream failure uses 0.

## Call the API

- GET https://api.duaer.com/v1/data/weather-history?place=Beijing&from=2024-01-01&to=2024-12-31&step=month
- Authorization: Bearer <Duaer key>

The call skill below matches Copy skill in the Duaer data market, with parameters, examples, and result fields.

## Call skill

Same text as Copy skill.

```
---
name: duaer-weather-history
description: >-
  Duaer Weather history. Past weather back to 1940 for any place: daily or monthly mean, high, low, and rainfall from the Open-Meteo reanalysis archive.
  One successful search uses 1 Duaer credit.
---

# Duaer Weather history

Duaer Weather history returns past daily or monthly weather for a place from the Open-Meteo historical archive (ERA5 reanalysis). Use `step=month` to fold a year or more into twelve readable rows.

## When to use

- Compare a season or a month with past years, or explain a sales or yield change by weather.
- Build a monthly climate table for a site before a visit, a harvest, or a construction plan.

## When not to use

- The next days. Use https://skills.duaer.com/weather.md.
- Recent days: the archive lags about five days behind today.

## Call

`GET https://api.duaer.com/v1/data/weather-history?place=Beijing&from=2024-01-01&to=2024-12-31&step=month`

Header: `Authorization: Bearer <Duaer key>`

Use an account key or a model API key.

Get a Duaer key: https://skills.duaer.com/keys.md

## Parameters

Provide `place`, or `latitude` and `longitude`, plus `from` and `to`.

- `place` — City or place name. Leave empty when you enter latitude and longitude.
- `latitude` — Optional. Decimal degrees from -90 to 90. Use with longitude instead of a place.
- `longitude` — Optional. Decimal degrees from -180 to 180.
- `from` — First day, YYYY-MM-DD. The archive starts in 1940.
- `to` — Last day, YYYY-MM-DD. Recent days appear after about five days.
- `step` — Optional. day or month. Month sums rain and averages temperature. Default day.
- `limit` — Optional. Rows to return, from 1 to 20. Default 10.

## Examples

- `GET https://api.duaer.com/v1/data/weather-history?place=Beijing&from=2024-01-01&to=2024-12-31&step=month` — monthly climate for 2024.
- `GET https://api.duaer.com/v1/data/weather-history?latitude=40.7&longitude=-74&from=2012-10-27&to=2012-10-31` — daily rows around a storm.

## Result

The response is `{ "items": [...] }`. Each item has `source`, `title`, `url`, and `summary`, plus:

- `place`, `latitude`, `longitude` — where the rows are for.
- `period` — YYYY-MM-DD for daily rows or YYYY-MM for monthly rows.
- `step` — day or month.
- `days` — days folded into the row.
- `temperatureMean`, `temperatureMax`, `temperatureMin` — °C. Monthly rows average the means and keep the extreme high and low.
- `precipitationMm` — total rain or snow water in mm.

Fields without a value are left out.

## Credits

A search that returns at least one row uses 1 credit.
An empty search, a search that finds nothing, or a failed search uses 0.
Wrong input returns 400 with a message and uses 0.
No remaining credits returns 402 and does not search.
A missing key returns 401.

## Related

- https://skills.duaer.com/weather.md — Duaer Weather forecast
- https://skills.duaer.com/river-flow.md — Duaer River flow

```
## Questions

### How many credits does a Weather history search use in Duaer?

One credit when Duaer returns rows. A search with no rows or an error uses 0.

### How far back does Duaer weather history go?

Duaer weather history reaches back to 1940 and ends about five days before today. One call covers up to ten years.

## Related

- [Weather forecast in Duaer](https://doc.duaer.com/getting-started/weather.md)
- [River flow in Duaer](https://doc.duaer.com/getting-started/river-flow.md)