> ## Documentation Index
> Fetch the complete documentation index at: https://docs.sunnymeteo.com/llms.txt
> Use this file to discover all available pages before exploring further.

# AQI hourly forecast

> Hourly air quality forecast for Chinese cities

## Overview

Returns hourly AQI forecast for up to \~5 days ahead.

| Item | Details |
| - | - |
| Coverage | Major cities in mainland China |
| Update frequency | About hourly |
| Timezone | Business times are usually Beijing time; station forecast store uses UTC and responses also include local time |
| Auth | `X-API-Key` header; module grant required |

### Related

* [AQI conditions](https://docs.sunnymeteo.com/en/products/air-quality.md)
* [City list](https://docs.sunnymeteo.com/en/reference/location-codes.md)

## Request

```
GET /v1/aqi/hourly
GET /aqi/hourly
```

### Query parameters

| Parameter | Type | Required | Description |
| - | - | - | - |
| `city_uid` | integer | one of four | Internal city ID (highest priority) |
| `city_code` | string | one of four | GB2260 admin code, e.g. `110000` |
| `city_name` | string | one of four | City name, e.g. `Beijing` |
| `lat` | number | with lon | Latitude -90\~90 |
| `lon` | number | with lat | Longitude -180\~180 |
| `format` | string | no | Response format: `json` (default) / `csv` / `tsv` / `xml` / `yaml` |

## Response

Shape: `{ city, hourly: { update_time, hourly[] } }`.

### `hourly[]` fields

Same as AQI conditions, plus:

| Field | Type | Unit | Description |
| - | - | - | - |
| `forecast_time` | string | ISO8601 | Forecast time |
| `update_time` | string | ISO8601 | Update time |
| `aqi` | number | — | Air quality index |
| `aqi_level` | number | 1–6 | Level number |
| `aqi_level_name` | string | — | Level name (Excellent / Good / Light pollution…) |
| `pm25` | number | μg/m³ | PM2.5 |
| `pm10` | number | μg/m³ | PM10 |
| `so2` | number | μg/m³ | Sulfur dioxide |
| `no2` | number | μg/m³ | Nitrogen dioxide |
| `o3` | number | μg/m³ | Ozone |
| `co` | number | mg/m³ | Carbon monoxide |
| `pm25_iaqi` | number | — | PM2.5 IAQI |
| `pm10_iaqi` | number | — | PM10 IAQI |
| `so2_iaqi` | number | — | SO₂ IAQI |
| `no2_iaqi` | number | — | NO₂ IAQI |
| `o3_iaqi` | number | — | O₃ IAQI |
| `co_iaqi` | number | — | CO IAQI |
| `primary_pollutant` | string | — | Primary pollutant |


This documentation is built and hosted on [Mintlify](https://mintlify.com), a developer documentation platform.