..
hasn't happened yet.
It's a fun law of thermodynamics that keeps us warmer than the valley floors where I grew up.. or at least became old. Halloween is my 'expected' time of frost, give or take a few days (i.e. whenever the skies clear up between storm fronts). It should be a full moon too, just to be right - and I should be listening to old Uriah Heep tunes!
Oops, mental derailment..
Life at 750' means watching most fog develop below our hill-top, where the cool air sinks and condenses. Cold-air drainage is the real deal, and we watch it frequently when the air-mass is relatively tranquil.
A few weeks back I saw a few light patches of frost in lower Longview, on well-drained bark dust. It didn't really count since it was so limited. They may have frosted last night, as the official readout showed 33° (all 'official' readouts come from at least three feet above ground level) and Scappoose came in at 28°. We stopped here at just under 35° - when I went to bed it was about there, and so it was this morning after several tiny fluctuations.
If the air got colder it slid downhill before reaching my semi-'official' readout on a 5-foot pole. Not much warmer in the hills with this pattern - but enough.
And so we continue to wait for our First Frost.