bad operand types for binary operator '>

Im trying to get this program to only print the numbers greater then 18 but I am abit confused on where to put the if ( temperature < 18) if you get me , I am only new to java and any help would be appreciated.

import java.util.Scanner;
class  L2TemperatureReading
{
    public static void main (String[] args)
    {
        Scanner input = new Scanner (System.in);

        double temperature[]=new double[7];

        for(int i=0; i<temperature.length; i++)
            {
                System.out.print("Max temperature for day " + (i+1) + ": ");
                temperature [i] = input.nextDouble();
            }

            System.out.println("**The temperatures entered**\n");

            System.out.println("The temperautures entered are as follows: \n");

            for(int i=0; i<temperature.length; i++)
            {
                System.out.println("Day " +i+ " = " + temperature [i]);
            }
        }
    }