Bike LED Headlight, Booties, Headbands, Skullcaps, Waterproof Jacket, Waterproof Pants, Waterproof Rain Gear, Bicycle Fenders, Bike Helmet Covers, Bike Rear light/Flasher, Biking Gloves, Long-sleeved Jackets, Goggles or Safety Glasses.
Ride slower in wet weather! When brakes become wet, stopping time increases. Take it slow and easy when it's raining; many bicycle brakes do not work so well in the wet. Go a little slower, think ahead and brake sooner.
Avoid Puddles (Puddles are deep potholes, and can conceal glass and treacherous things.) Avoid manhole covers (or any metal on the road/painted traffic markings, etc), they become particularly slippery. Keep your bike upright and stop pedaling, don't brake or turn when crossing these slippery surfaces.
Wet leaves and oil are dangerous! Rains tends to lift a lot of the oil from the road, making it even more slippery - so pay extra special attention!
Rain means reduced visibility. If you're cycling on the road it's a very good idea to use lights or some sort of high-Visibility clothing to increase your visibility to other road users!
A Rain hood is dangerous, because it can block your view when you turn your head. A Rain cape/Jacket should be bright yellow, to make you more visible to drivers. Pay special attention to motor vehicles when it rains!
Toe covers and shoe covers are helpful if you wear biking shoes; if you don't, any footwear that keeps you warm will do.
Warm, comfortable clothing. The first type of clothing is for warmth, the second to block the wind/Rain.
Jackets: Cold Rain Weather - A good waterproof cycling jacket will keep the rain off you.
Bicycle Maintenance: Rain Cleaning (relubricate your bicycle's chain to help prevent rust).
Rain weather cycling is fun but Safety is important.
Good luck to you all, and hope to see you in the future."