I was out in six to eight foot waves and 30-35 knots out of the east
(long fetch for here) in mid-October and we had a hell of ride down to
Toronto.

Six to eight foot waves are commonplace on the Atlantic, and are to be
expected any time the wind blows 15 kts or more for over a few hours
time. They are not gentle rollers either. The REALLY nasty stuff
(over 20 feet) happens with winds over 35 kts for a day or so.

The ocean pilot charts used to list the percentage of time that gale
force winds could be expected for any given location and month. I'm
not sure if they are still available or not, but there are no months
when the probability is zero.