Rainfall

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package javaapplication1;

import java.util.Scanner;

public class RainFall {

    /**
     * @param args the command line arguments
     */
    static double total = 0;
    public static double monthsOfRainfall[] = {1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12};

    public static String monthsNames[] = {"January", "February", "March", "April", "May", "June", "July", "August", "September", "October", "November", "December"};

    public static void main(String[] args) {

        yearlyRainfall();
        averageMonthlyRainfall();
        highestMonth();
        lowestMonth();
    }

    public static void yearlyRainfall() {

        Scanner input = new Scanner(System.in);

        for (int i = 0; i < monthsOfRainfall.length; i++) {

            System.out.println("Enter the rainfall for month " + (monthsNames[i]));

            monthsOfRainfall[i] = input.nextDouble();

            if (monthsOfRainfall[i] < 0) {
                i--;
                System.out.println("Error, Invalid Input. Re-Enter integer between 0 and ∞.");
            } else {

                total += monthsOfRainfall[i];
            }

        }
        System.out.println("*********************************");
        System.out.println("The total rainfall for the year is: " + total);

        System.out.println("*********************************");

    }
    //METHOD TO KNOW THE AVERAGE RAIN IN X MONTH

    public static void averageMonthlyRainfall() {

        System.out.println("The average monthly Rainfall is " + total / 12);
        System.out.println("*********************************");

    }
    //METHOD TO KNOW THE HIGHEST RAIN MONTH

    public static void highestMonth() {

        double highest = monthsOfRainfall[0];

        String whatmonth = monthsNames[0];
        int i;

        for (i = 0; i < monthsOfRainfall.length; i++) {

            if (monthsOfRainfall[i] > highest) {
                whatmonth = monthsNames[i];
                highest = +monthsOfRainfall[i];

            }

        }
        System.out.println("The Highest month is " + whatmonth + " with a rainfall of: " + highest);
    }

    //METHOD TO KNOW THE LOWWEST RAIN MONTH
    public static void lowestMonth() {

        double lowest = monthsOfRainfall[0];
        String whatmonth = monthsNames[0];
        int i;

        for (i = 0; i < monthsOfRainfall.length; i++) {

            if (monthsOfRainfall[i] < lowest) {
                whatmonth = monthsNames[i];
                lowest = monthsOfRainfall[i];
            }

        }

        System.out.println("*********************************");
        System.out.println("The Lowest month is " + whatmonth + " with a rainfall of: " + lowest);
    }

}

//NEED HELP WITH WHAT EXAM NUMBER IS HIGHER OR LOWER.