Hmm..Tamil is available in the translation project, see http://translate.windy.com/collaboration/translate/project/project/98751/language-from/1/language/33
and i think in settings too (can't read that)
0_1517496155007_2018-02-01 15_41_27-Windy_ Settings.png

If i choose that..that's happen:
0_1517496270388_2018-02-01 15_43_51-Windy_ Settings.png

Whats happen if you choose that language?