请以json格式提供重庆的气候特点
user
```json
{
  "city": "重庆",
  "climate_characteristics": {
    "type": "亚热带季风气候",
    "seasons": {
      "spring": "温暖湿润，降水适中",
      "summer": "炎热多雨，气温高且湿度大",
      "autumn": "凉爽干燥，气温宜人",
      "winter": "温和少雨，偶尔有雾"
    },
    "highlight": "常年多云雾，湿度较高，雨量充沛"
  }
}
```
assistant