airliners are not allowed to takeoff or land in freezing rain...if you are at an airport and the freezing rain has stopped in the opinion of the pilot, then you can request a special weather observation to confirm that the freezing rain stopped... you could also make aPIREP and say...freezing rain has stopped
then you takeoff.
I have seen idiot pilots insist that there was no freezing rain, then I opened the sliding window (DV) stuck my hand out (onthe ground) and felt the stinging freezing rain...
there are idiot pilots out there.
j