I like the recreational aspects of riding a motorcycle on the weekends, after work and on the occasional longer trip. That type of riding is generally the most fun if it's sunny or at least not raining - although running into rain is part of the deal too.
What I really like though is just riding a motorcycle anytime. For that reason I've become a utility rider - meaning I use a motorcycle to get to work and run errands whenever possible, which is any day when there's not snow, frost or ice on the roads. In the last couple of years I've probably driven a car to work about ten times, so I'm pretty lucky.
Living in the Pacific Northwest and wanting to ride a motorcycle as much as possible means you'll be riding in the rain. That's really not a problem as long as you have the right gear and keep in mind some basic safety rules - the main one being to adjust your speed for road and traffic conditions. In the MSF operators course they recommend not riding immediately after the rain starts. The reason for this is the oil, transmission fluid, diesel, etc. that leaks out of vehicles onto the road can combine with the water to create some extra slippery conditions.
This is not usually much of an issue in this area (particularly in the fall/winter/spring) since the rain tends to last for awhile and will wash the road relatively clean. Yesterday was an exception.
There was a light mist that caused the road to be wet but not enough rain to clean it off. There's a right hand curve shortly after the parking lot where my bike had been sitting for the day. As I pulled out of the lot and accelerated to get in front of cars approaching I entered the curve. The tires started to lose traction causing a sideways slide and I ended up crossing the center line which was not catastrophic since there was no on coming traffic and the bike stayed upright.
It was a good reminder though. I'm not sure if I picked up some oil on the tires in the parking lot or if it was on that corner - but in any case it was more slippery than I anticipated. I've ridden around that corner hundreds of times and have a good idea of how fast I can ride it - except for yesterday. This is the second time fairly recently that I've learned how slick the pavement can be when it's wet. The other time was coming to a stop sign at a slow rate of speed immediately after having the bike parked on a rainy day. I was surprised that even moderate braking caused the bike to slide. This was another case where vehicles had left a nice slippery spot of oil/diesel from sitting at that stop sign.
I'm amazed sometimes when riding in urban areas to see how much oil/diesel/transmission fluid, gear oil (or whatever it is) is left on the road. I'm not sure how vehicles keep running when they are dripping fluid that leaves spots a foot or two in diameter every twenty feet or so. Whoever is driving those must be adding fluids on a regular basis.
One other consideration when riding in the rain is visibility - seeing/being seen. Riding at night in the rain is a no-no for me in general, although if I have to I will, for as short a time as necessary. I don't like to ride in heavy high speed traffic in some rain conditions - particularly when the temperature is causing ground fog, or my visor/glasses are fogging up or then there is a lot of fine spray from cars moving in adjacent lanes that tends to stay in the air and compound the difficulty of seeing/being seen.
The bottom line is there is no reason that riding in the rain can't be safe and enjoyable - just be aware of road conditions, your bike's capabilities, your riding skill and adjust your speed and following distance accordingly.