Charlie,
   its hunt weekends or bust for me can't let rain slow me down. also trail cams showing all 4 bucks still working the small area as well as does. i put out another stand today in the pouring rain to cover wind direction and give me another option. i can feel it man just need to get my azzz in the stand no matter what!

A lot of good advice here, but the determination you have is outstanding! Go get'm    

if it's raining hard, the deer will be bedded down. be there as soon as it stops.

Wool clothing in the rain will keep ya warm even when wet.It's also very quiet.

If your hunting your stands just keep at it, dress warm and wear something to help keep you dry but quiet ... if still hunting keep the wind in your face. Rain can be a good thing to keep the ground quiet and maybe knock a few leaves down for you.

If you get lucky and have to blood trail a critter, mark your starting point with something the rain will not wash away and move quickly along the side of your blood trail. If it's good blood trail, my experience is you will not have an issue, but if it is sparse mark your route you go can clearly see the travel line.

Good luck

Its not the rain you have to worry about.

Make sure you take your bonine pills and tie yourself tight to the trunk.
Good luck and may your arrows fly true.

I used a tree umbrella for the first time in August this year.  A great invention!  I sat in rain off and on from about 1:00 until about 9:00. I stayed comfortably dry.

Wait for it to quit! Unless your in Western Washington or Oregon, then wait for it to slow down!

Other tip I have is to use this stuff to water proof your feathers. Make sure you by the fabric one like in the picture. Apply it outside in accordance with the instructions and let it stay outside for 24 hrs!

Still hunting works well in the rain but, be aware your senses get confused to. Hard to spot deer standing still with all that movement so go slow and stay frosty! Also I like to use baby bottle liners for fletching covers. I put them over the fletching and use a little rubber band to secure to the arrow. Just pull the cover off the rubber band will stay attached but, if it's nice and small it won't affect anything.

I'm surprised nobody has mentioned Luminol aka Bloodglow.
The stuff is absolutely amazing and it's not a gimmick. It is used by law enforcement to locate blood. Criminals try to wash away blood at crime scenes but Luminol still detects it. You mix tablets with water (but windshield washer fluid is better) in a spray bottle. It is used in darkness (no lights at all) and glows blue when it contacts blood drops smaller than the eye can see. And rain does NOT wash away the iron(?) in the blood that Luminol detects. In fact, rain makes the blood easier to see with Luminol.
We did a test trail by putting some blood on a rag and dragged it through the woods. There was absolutely zero blood that was visible by the naked eye. We came back after dark and sprayed Luminol and the trail glowed an easy to see blue. But what was even more amazing was the following day we got almost an inch of rain...We went back that 2nd night and the test trail was still easily seen.
If there is or was blood, Luminol WILL detect it. Even on your hands after washing with soap and water!
2 tablets will cover approx 100 yards (so they say) and cost about $25 for a package of 8 tablets (4 mixes) so you can possibly trail 400 yards for $25.
Go to bloodglow.com
Every hunter needs to know how to blood trail but this stuff is an amazing last resort when you can't find blood.