Best not to go there as it provokes some debate from it's fans, but IMO it's an aid to fitness, it's NOT cycling

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That's where I am. It's hardly stopped raining for weeks now, and the wind....
I have goretex cycling stuff which was not cheap, but nothing is going to stop water eventually getting in around your collar. As for Aldi or Army surplus
@Old Hippy , no way is that going to be breathable, in which case you are going to boil in the bag and be just as wet from sweat as you would be from rain. Maybe ok in areas with no hills so you can just back off on the effort, but I don't have that option.