无法执行看起来很简单的HTTP POST到openweathermap.org

我的Angular服务组件中的功能是向openweathermap.org发出POST请求以创建新的天气站：

registerStation(registerWeatherStation: RegisterWeatherStation): Observable<Response> {
let params = JSON.stringify(registerWeatherStation)
console.log("params: ",params)
let header = new Headers({'Content-Type': 'application/json; charset=utf-8'})
let options = new RequestOptions({ headers: header })
let url = this.servUrl + 'stations?appid=' + this.weatherAppId
return this
    .http
    .post(url, params, options)
}

这是来自Chrome的Developer工具网络标签，显示由上面的功能触发的活动。我认为这显示了我的预检测请求，openweathermap.org的预检测响应，以及我的请求标头：

Preflight Request???
request url: http://api.openweathermap.org/data/3.0/stations?appid=xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
Request Method: OPTIONS
Status Code: 404 Not Found
Remote Address: 162.243.53.59:80
Referrer Policy: no-referrer-when-downgrade

Response Headers
Access-Control-Allow-Credentials: true
Access-Control-Allow-Methods: GET, POST, PUT, DELETE
Access-Control-Allow-Origin: *
Connection: keep-alive
Content-Length: 42
Content-Type: application/json; charset=utf-8
Date: Thu, 24 May 2018 19:57:00 GMT
Server: openresty

Request Headers
Accept: */*
Accept-Encoding: gzip, deflate
Accept-Language: en-US,en;q=0.9
Access-Control-Request-Headers: content-type
Access-Control-Request-Method: POST
Connection: keep-alive
Host: api.openweathermap.org
Origin: http://localhost:54270
User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/66.0.3359.181 Safari/537.36

这是我从Postman中执行的POST的代码片段，该代码段从openweathermap.org获得了有效的响应：

POST /data/3.0/stations?appid=xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx HTTP/1.1
Host: api.openweathermap.org
Content-Type: application/json
Cache-Control: no-cache
Postman-Token: 25e03224-a9e7-43af-9757-dc37c41af780

{"external_id":"Paula's_Ranch_1","name":"Paula's Ranch Weather","latitude":xx.155012,"longitude":-xxx.976649,"altitude":100}

我做错了什么？我应该从我的后端执行POST吗？