They tend to stay under cover a bit more when it's raining hard. Just dreary drizzle na, they get out in that. If it's hot out, they will get out in the rain to cool off and find/make mud holes. As far as scent goes, the rain will knock down/cover your scent on the wind a little bit but not a whole lot more. But water will actually trap your scent on the ground. Hence why rabbit hounds track 100 times better in dew fall cover.