double[] temperatures = new double[31];
//double input = 0;
//for (int i = 0; i < temperatures.Length; i++)
//{
//    do
//    {
//        Console.Write($"Please, enter a value for [-100, 100] temperature[{i}] = ");
//        input = double.Parse(Console.ReadLine());
//    } while (input < -100 || input > 100);
//    temperatures[i] = input;
//}

//for (int i = 0;i < temperatures.Length; i++)
//{
//    Console.WriteLine(temperatures[i]);
//}

Random Random = new Random();
for (int i = 0; i < temperatures.Length; i++)
{
    temperatures[i] = Random.Next(-100, 100);
    Console.WriteLine($"Farenheit = {temperatures[i]}");
    Console.WriteLine($"Celsius = {CelF(temperatures[i])}");
}

static double CelF(double f)
{
    return (5.0/9) * (f - 32);
}