My keyless entry works as normal with outside air temperature in the upper 70s or above. Cooler temperatures the keyless entry is inoperative. New key fob, new batteries. Any help will be greatly appreciated.
Thank you.

 

I'm not too familiar with this system, but is the error correlated to temperature or humidity?

And when you say "inoperative" is it that there is no indication of the security light even coming on on the dash when you depress the fob button or any noises as if the locks are trying to unlock?

 

Give this a try:
Open the key fob, carefully!
Use some 90% alcohol and Q-tip, clean the circuit traces under the push buttons and wipe off the push buttons as well.
Take a good ole' #2 pencil and go over the ends of each push button.
Put key fob back together, see if it works any better.