百度有个API store,专门为开发者提供API服务，网址为：百度API Store。

http://apistore.baidu.com/astore/serviceinfo/1798.html

1 接口说明

　　根据经纬度/城市名查询天气的结果

2 接口示例

http://api.map.baidu.com/telematics/v3/weather?location=北京&output=json&ak=yourkey

百度ak申请地址：

http://lbsyun.baidu.com/apiconsole/key

3 接口参数说明

4 返回结果

返回JSON格式的数据

{
    "error": 0,
    "status": "success",
    "date": "2016-07-19",
    "results": [
        {
            "currentCity": "北京",
            "pm25": "105",
            "index": [
                {
                    "title": "穿衣",
                    "zs": "舒适",
                    "tipt": "穿衣指数",
                    "des": "建议着长袖T恤、衬衫加单裤等服装。年老体弱者宜着针织长袖衬衫、马甲和长裤。"
                },
                {
                    "title": "洗车",
                    "zs": "不宜",
                    "tipt": "洗车指数",
                    "des": "不宜洗车，未来24小时内有雨，如果在此期间洗车，雨水和路上的泥水可能会再次弄脏您的爱车。"
                },
                {
                    "title": "旅游",
                    "zs": "较不宜",
                    "tipt": "旅游指数",
                    "des": "温度适宜的一天，风力不大，但有较强降水，会给您的出行产生很多麻烦，建议您最好还是多选择在室内活动吧！"
                },
                {
                    "title": "感冒",
                    "zs": "易发",
                    "tipt": "感冒指数",
                    "des": "相对于今天将会出现大幅度降温，空气湿度较大，易发生感冒，请注意适当增加衣服。"
                },
                {
                    "title": "运动",
                    "zs": "较不宜",
                    "tipt": "运动指数",
                    "des": "有较强降水，建议您选择在室内进行健身休闲运动。"
                },
                {
                    "title": "紫外线强度",
                    "zs": "最弱",
                    "tipt": "紫外线强度指数",
                    "des": "属弱紫外线辐射天气，无需特别防护。若长期在户外，建议涂擦SPF在8-12之间的防晒护肤品。"
                }
            ],
            "weather_data": [
                {
                    "date": "周二 07月19日 (实时：23℃)",
                    "dayPictureUrl": "http://api.map.baidu.com/images/weather/day/dayu.png",
                    "nightPictureUrl": "http://api.map.baidu.com/images/weather/night/dayu.png",
                    "weather": "中到大雨转大雨",
                    "wind": "微风",
                    "temperature": "26 ~ 22℃"
                },
                {
                    "date": "周三",
                    "dayPictureUrl": "http://api.map.baidu.com/images/weather/day/dayu.png",
                    "nightPictureUrl": "http://api.map.baidu.com/images/weather/night/zhenyu.png",
                    "weather": "大雨转阵雨",
                    "wind": "东北风3-4级",
                    "temperature": "25 ~ 22℃"
                },
                {
                    "date": "周四",
                    "dayPictureUrl": "http://api.map.baidu.com/images/weather/day/zhenyu.png",
                    "nightPictureUrl": "http://api.map.baidu.com/images/weather/night/duoyun.png",
                    "weather": "阵雨转多云",
                    "wind": "微风",
                    "temperature": "31 ~ 22℃"
                },
                {
                    "date": "周五",
                    "dayPictureUrl": "http://api.map.baidu.com/images/weather/day/duoyun.png",
                    "nightPictureUrl": "http://api.map.baidu.com/images/weather/night/duoyun.png",
                    "weather": "多云",
                    "wind": "微风",
                    "temperature": "32 ~ 25℃"
                }
            ]
        }
    ]
}