Translation:It rained this evening.
"It was raining" is past progressive, ふってった. ふりました is simple past, "it rained". I've seen different opinions in the comments on whether English past progressive should be accepted, and I don't know enough Japanese to have an opinion of my own. I thought it might help if I outlined the difference between simple and progressive, however.
What a strange thing to say, normally in English you'd just say "it rained today" or "it rained yesterday" unless it was at night, is it common to specify evening this way in Japanese? When even is evening? I can't imagine myself ever using konbanwa as something in the past, maybe something in the immediate future like "this evening could you help me do xx" but even then I'd probably just say "later"