As long as I can keep myself dry and warm I quite like walking in the rain. I don't mind cycling in it either but find keeping warm & dry without the boil-in-the-bag effect is a tad more tricky.
I think non boil in the bag cycling kit is hard to find. Harder than walking/mountain kit.
Summer cycling in the rain is OK, just get wet. In fact some of my best club times have been set in heavy rain, I think the cooling improves my performance, where heat seriously saps it.
For the rest of the season good kit costs. I rashley spent just short of £200 on a Paramo Velez light smock for primarily cycling/audax usage and dog walking/camping etc as a secondary use.
It was money bloody well spent. On the bike it's ace, comfortable, warm when required, vents and wicks well and absolutely 100% waterproof. Down side is that if you need to take it of it's bulky, but you rarely need to remove it unless it's really warm. Last Sundays fastish club run saw regular stops to don or remove waterproofs, all I needed to do was open or close zips as conditions changed. Ace.
In Sweden where we lived they said there was no such thing as bad weather, just bad clothing ....