there was a temperature reading of 0 degrees (-0.5, 0.5) at the windsor airport for about 6 hours early this  morning. if i had plants, i would want to protect them, but i'm not sure that qualifies as technical frost. it would be as close to frost as possible, certainly.

it's nov 14th. that's the closest we've been so far. it may get close again for the next few nights before the temperature rebounds, but the forecasts are different on different sites. 

the soonest forecast for -1 that i can find is nov 27th which is too distant.