Frog floater this morning in Washington, DC. After the first quarter mile, I decided it would be good to have the lights on, even though it was 8 AM. By the next quarter mile, I could not imagine riding without them on. The street lights were all on -- it really looked like 9 PM. However, the rain was very light for the next few miles. When it finally did hit, within a few minutes there was a foot of standing water in some spots. Fifteen minutes later, it had stopped.
Gor-tex and lights are your friends.
Paul