why is it giving me an error saying "Did you forget to return weatherForecast?"

using System;
using System.IO;

namespace Treehouse.CodeChallenges
{
    public class Program
    {
        public static void Main(string[] arg)
        {
        }
    }
}

using System;

/* Sample CSV Data 

weather_station_id,time_of_day,condition,temperature,precipitation_chance,precipitation_amount
HGKL8Q,06/11/2016 0:00,Rain,53,0.3,0.03
HGKL8Q,06/11/2016 6:00,Cloudy,56,0.08,0.01
HGKL8Q,06/11/2016 12:00,PartlyCloudy,70,0,0
HGKL8Q,06/11/2016 18:00,Sunny,76,0,0
HGKL8Q,06/11/2016 19:00,Clear,74,0,0
*/

namespace Treehouse.CodeChallenges
{
    public class WeatherForecast
    {
        public string WeatherStationId { get; set; }

         public static WeatherForecast ParseWeatherForecast(string[] values)
         {
            WeatherForecast weatherForecast = new WeatherForecast();

            weatherForecast.WeatherStationId = values[0];

            return weatherForecast;
         }
    }
}