I have a 2D array with every element that is a string, I need to convert the strings that contain numbers into integers.

```
String[][] weatherData = [["London", "23", "11", "10.1"],["Tokyo","21", "9", "11"], ["Cape Town", "31", "12", "21"]]

```

The first element of each array is the city name, the second is the highest temperature, the third is the lowest temperature and the fourth is the rainfall. 

I need to convert all the number values to integers and then search the second element (highest temperature) of each array to find the highest temperature of the whole weatherData array and display that temperature. 

If anyone can help that would be great!