Is nature's way of telling you you're not getting a flying lesson in this morning. The presence of ice forming on aircraft not rated for flying in known icing conditions does not mix, at all.
The day started reasonably nice with a wind from 15-25 along 270-250 degrees so practically down the runway - ok for a lesson but past my solo endorsement. It's clear, a bright day with a layer at about 3,000.
So a good pre-flight, start up, and a little rain starts to fall but everything is reported and still appears VFR with about a 3,000 foot ceiling, good enough for pattern work. We get to the run-up area and....
Hey, where did the end of the runway go?
We wait for a bit and Tower reports they've still got good visibility and then we notice that while it's raining a bit more, and we're getting some carburetor ice from the moisture in the air and then...the temperature visibly falls.
"We're now picking up ice".
"Yep. we're done"
So taxi on back and we let the Tower know about the icing conditions and the Tower announces they're going IFR, so we go inside for a ground lesson where I did quite well.