We looked up and there was some patches of "blue" sky so only showers.
The rain stopped and we went back on court, took out a can of Head Instinct balls (had been used the day before!)
Started playing these balls where great, didn't pick up a lot of water and the balls stayed light (not heavy when wet!)
The biggest point is these balls are only £2 a can (4 balls) from Amazon (Millets)
I have ordered another 10 cans for the winter :-
Hope this helps!