So you've got your loadout sorted, you have 3 spare rifles for every skirmish, you're an experienced Airsofter... But it's raining... Aaaand it's cold... Still with me? Good!
There is an old saying, "There's no such thing as bad weather, just the wrong clothing!" this holds incredibly true for the last skirmish we played, tipping down with rain all day, wet through is an understatement, yes skin is waterproof, but not cold proof too! Also if you're carrying an AEG, especially if you have a mosfet controlled one, you have a gun that is possibly (although very unlikely) could short circuit and fry a battery or shoot your team mates in the leg should it short circuit in the worst way!
40 minutes in the rain without a contact makes anybody cold, unless you're properly togged up, warm & waterproof is worth a decent investment! It's even worth making sure your mags stay dry and your gun barrels are pointed down, wet BBs make for some very interesting flight patterns! 15-20 feet then turning a random right angle in the air type stuff!
So next wet game you're looking at (in this country the next few!) prepare, prepare, prepare, get yourselves a decent waterproof top (at the very least), make sure your electronics are sealed up nicely (exposed mosfets in heatshrink, any bare wires etc), keep your ammo dry and watch where you tread cause in addition to all of that it will get very slippery underfoot too!
I've played in every condition from 30 degree heat to torrential rain to thick snow on the ground (not played in a blizzard yet, but wouldn't that be awesome?). The only thing to really affect how you plan your clothing is rain, any extreme of temperature can be dealt with by adding or subtracting layers, rain changes completely what your top layers need to be, how you access & how you prep your kit.
All that said stalking someone through the woods in torrential rain with your M16 under your arm is a whole reward in itself, a rainy day if prepped for properly can be awesome on another level!
Just don't let your mesh get rusty!
See ya next time.