Generally, all my cycling experiences are enjoyable except where crashes or mechanical failures have occurred. I cannot control the weather so in good or bad conditions, weather only added to the challenge and did not detract from the overall experience (except nearly getting frostbite once).
My most recent adventure was 2 days ago riding the paved (there is a parrallel dirt path also for bikes, horses, etc.) Jacksonville-Baldwin Rail Trail at night under a waxing gibbous moon. Quiet and cool conditons perfect for riding. I use no lights or reflectors (I am on my racing bike; none are mounted) and as a youth I toured in the same manner riding at night to make it to the next destination.
Hazards are many and even in the moonlight (70% of the trail is dark from the overhanging tree canopy) it is hard to see them: pebbles, branches, misc. debris, pavement damage, wildlife, etc.
I ride at my normal speed of 16-18mph just like daytime riding.
I personally find it invigorating as well as a bit eerie.
Just a note: the trail is closed between sunset and sunrise so I may be violating some local law, but my taxes pay for its upkeep and I work during daylight so moonlit nights are great way for me to continue a training regimen without having to add extra mileage during weekend rides. Including the photos to add some perspective.
I warn others that if you do this type of riding you are taking a certain added level of risk over regular daytime riding which is risky enough and nightime riding with proper lighting. NEVER DO THIS ON ROADWAYS; plus it is against laws in most States/areas to ride on public roads without lights.
I am not sure that it is any more dangerous than riding in vehicular traffic, but I would rather get hit by, or hit a deer than to have an interaction with a car.