The last of the ice has melted, so here's my rating:
If I were comparing it to my whole life so far, including the 80s and 90s, it would have barely scraped a 2/10. That's mainly for the frost persisting and building up over several days, plus the freezing fog yesterday - something which is and always has been rare here.
But it's not the 80s or 90s any more, snow on the ground at 9 AM is now a 1-in-4 or 5 year event, and as such measuring it against the past 15 years comes up with a much higher result - 7/10, I would say. Points gained for:
* A brief dusting of snow at half past midnight right at the start - good job I had my Nest cam going! That made it the snowiest spell for 4 years.
* More than the traditional "three frosts and it wets itself" type of cold spell (it started off that way, had a blip, then came back even colder).
* Frost persisting on the lawn for three days, ending up looking for all the world like a heavy dusting of snow (even down to the "crunch" as you walk on it). Ice developed on ponds etc and stayed there throughout the coldest part of the spell.
* An interesting transition to and from the mild blip on Sunday/Monday - going from 5 to 11 in just an hour or so on the way up, and 11 to 4 in an hour on the way down. Shame about the gales that accompanied the latter!
* A 3-day 1-minute mean temperature of -0.9, and a 4-day of -0.2 - very unusual these days.
* Freezing fog and rime
* A daytime max of 1.0 - as close to an ice day as you're going to get without snow on the ground.
And above all, it actually *felt* like winter - for 10 glorious cold days, plus the day or so where it reverted to autumn and then went back to winter, a remarkable experience and more like a Continental climate than the good old UK. The run up to it was good, as well, and more widely there was noteworthy cold in the north. I've enjoyed it very much, and I think it's about as good as you could get without a proper snow covering.
For those wondering what would give a higher score, a few inches of snow would add a point, an ice day would add a second and the third and final one would come from an easterly/northerly reload.