Add your own weather icons.

make sure you follow the existing naming convention:

folders: the name should always start with the word "pack" followed by a number, just not one already used. for instance folder name "pack5" 
images: 01d.png 02d.png etc. the d and n designate day and night. follow existing images for names. 

in the weatherWidget.html file change the iconPack = x;  to your pack number. for the example above: var iconPack = 5;