Originally Posted by
elcruxio
Like others have mentioned it really depends on the temperature but one may need to factor in changin conditions. Where I live just relying on the weather history worst case may not work out since sometimes interesting weather happens. I don't know how common this phenomenom is globally, but it pretty much happens every summer when a warm summer day can rapidly in under an hour turn into almost winter like. Something to do with a cold layer of air pushing down rain so you get both freezing heavy rainfall and cold air which can drop temperatures drastically. Also a warm summer rain is unheard of here. All rains are cold.
certainly I have had lots of situations where summer rainstorms can turn rather cold suddenly, and this is why I put the importance of having with me the helmet cover, fleece neck buff, some polypro gloves+dishwashing gloves and base layers top and bottom that will work well when damp for keeping me from getting chilled.
gauvins, I always remember on one of the Velo Quebec "Grand Tours" that my wife and I did, beginning of August (so nice and hot) and on the first day a big thunderstorm came and the temperatures dropped from sunny and hot down to pouring rain, wind and below 20c, and so many people had not brought rain gear, mostly the roadies, and there were loads and loads of really miserable frozen riders standing around under any shelter they could find, waiting for the support vans with trailers for bikes to pick them up (camions d"abandon).
it was a classic weird august rain storm, warm at first, but then getting colder and colder. I started first with the usual rain jacket, pants and rain booties, but ended up stopping and putting on helmet cover and then finally with frozen hands, putting on the polypro gloves inside the dishwashing gloves.
It was also unusually long lasting, and the rain continued on all afternoon and evening, which is not normally the case with our "summer storms".
Usually in our summer around here, you'll get a big storm, then it will clear and the sun will come out again, and you can warm up and even dry out stuff hanging it in the sun when you take a snack break.