signal loss

What would cause a 900 ap’s uplink and downlink power levels to drop approx. 15 db, but then return to normal when it rains or is cold?

Thanks in advance,

Are you referring to uplink and downlink percentages or receive/transmit signal levels?

Signal levels. On a nice day, I have a client that normally runs in the mid to low 60’s, but recently thy’ve been running in the mid to high 80’s.
Except when it rains or the temp dips into the teens. And it’s not just one client, some are affected more than others, but all are affected.

I’ve replaced everything except the omni. Been a little too windy lately to change that. I’m thinking that the antenna could possibly be bad.
What’s got me stumped though is that it works great in the rain. I’m thinking it should be opposite, or am I wrong here?