50 degrees and raining this morning. Wore my waterproof hiking boots instead of my SPD shoes. Same boots I'll wear when it's -20 °F. If I had a nice pair of waterproof (or mostly waterproof) cycling shoes or boots, I might have worn them instead, but they cost some $$$$. If I lived in a climate where I could expect a lot of 40 and 50 degree rainy weather I might invest in some.

For us winter means temps below freezing most of the time and often slippery conditions. I'm not a big fan of SPDs in that kind of weather so I switch to platforms. Some folks still prefer SPDs in the winter.