Season is not abstract and does not override abstract method printMonths() in Season

"Write an enum named Season with 4 constants: WINTER, SPRING, SUMMER, FALL. It contains a final field named averageTemperature, initialized by a constructor and with a getter method. Additionally, it also contains an abstract method named printMonths() which will display the months in that respective season. Traverse all values of this enum and display the season, average temperature, and the months of that season."

public enum Season {
    WINTER(-5.0, new String[]{"December", "January", "February"}),
    SPRING(15.0, new String[]{"March", "April", "May"}),
    SUMMER(25.0, new String[]{"June", "July", "August"}),
    FALL(10.0, new String[]{"September", "October", "November"});
    @Override
    public abstract void printMonths(){
        this.months = months;
        this.averageTemperature = averageTemperature;
    };
    private final double averageTemperature;
    private final String[] months;

    Season(double averageTemperature, String[] months) {
        this.averageTemperature = averageTemperature;
        this.months = months;
    }

    public double getAverageTemperature() {

        return averageTemperature;
    }

    public void printInfo() {
        System.out.println("Season: " + this.name());
        System.out.println("Average temperature: " + this.getAverageTemperature() + " degrees Celsius");
        System.out.print("Months: ");
        this.printMonths();
        System.out.println();
    }
}

As the method is abstract, it shouldn't have a body and should be implemented in each instance : each season

enum Season {
    WINTER(-5.0) {
        @Override
        public void printMonths() {
            System.out.println("December, January and February");
        }
    },
    SPRING(15.0) {
        @Override
        public void printMonths() {
            System.out.println("March, April and May");
        }
    },
    SUMMER(25.0) {
        @Override
        public void printMonths() {
            System.out.println("June, July and August");
        }
    },
    FALL(10.0) {
        @Override
        public void printMonths() {
            System.out.println("Septembre, October and November");
        }
    };

    private final double averageTemperature;

    Season(double averageTemperature) {
        this.averageTemperature = averageTemperature;
    }

    public abstract void printMonths();

    public double getAverageTemperature() {
        return averageTemperature;
    }

    public void printInfo() {
        System.out.println("Season: " + this.name());
        System.out.println("Average temperature: " + this.getAverageTemperature() + " degrees Celsius");
        System.out.print("Months: ");
        this.printMonths();
        System.out.println();
    }
}

Then use like

for (Season s : Season.values()) {
    s.printInfo();
}

<!-- -->

Season: WINTER
Average temperature: -5.0 degrees Celsius
Months: December, January and February
Season: SPRING
Average temperature: 15.0 degrees Celsius
Months: March, April and May
Season: SUMMER
Average temperature: 25.0 degrees Celsius
Months: June, July and August
Season: FALL
Average temperature: 10.0 degrees Celsius
Months: Septembre, October and November