using System;

using Newtonsoft.Json;

​

public class Program

{

    public static void Main()

    {

        object[, ] arrayTemperatura = new object[5, 3]{{"09/18", 95, 95}, {"10/18", 257, 257}, {"11/18", 1368, 1368}, {"12/18", 1574, 1574}, {"01/19", 2437, 2437}};

        string jsonNet = JsonConvert.SerializeObject(arrayTemperatura);

        Console.WriteLine(jsonNet);

    }

}