请以json格式提供北京今天的天气情况，包括最高温度、最低温度和天气描述。
user
```json
{
  "location": "Beijing",
  "date": "today",
  "weather_description": "sunny",
  "temperature": {
    "high": "25°C",
    "low": "15°C"
  }
}
```
assistant