Isn't the annoying thing about rain at this time of year that you have no choice to get wet? It's so warm that if you put on waterproofs you end up in a sodden sauna inside them, and if you do without you get soaked from the rain. When it's raining in winter, it's cold and you don't get so sweaty underneath the waterproofs. At least then there's a choice about keeping dry.
Yesterday I wore a waterproof jacket and Goretex trousers. The jacket kept the sweat in and soaked my top half. The trousers channelled most of the rain into my boots and let the rest through onto my shorts.. When I got to work I changed everything I was wearing.