I can't predict the weather, but on a summer night ride you can usually get away with two thin cycling jerseys. On the first half of the Dunwich Dynamo, for instance, I tend to wear just a short-sleeved jersey and put a long-sleeved one on top of that for the second half.
(I wouldn't wear jeans on a ride like this, unless you're happy with them scraping across your knees, and if it's wet, you can get into some serious pain that way.)
I can't predict the weather, but on a summer night ride you can usually get away with two thin cycling jerseys. On the first half of the Dunwich Dynamo, for instance, I tend to wear just a short-sleeved jersey and put a long-sleeved one on top of that for the second half.
(I wouldn't wear jeans on a ride like this, unless you're happy with them scraping across your knees, and if it's wet, you can get into some serious pain that way.)