请告诉我今天北京的天气情况，使用json格式
user
```json
{
  "city": "北京",
  "date": "2023-10-05",
  "weather": {
    "description": "多云",
    "temperature": {
      "current": "22°C",
      "high": "25°C",
      "low": "18°C"
    },
    "humidity": "60%",
    "wind": {
      "speed": "12 km/h",
      "direction": "东南"
    }
  }
}
```
assistant