Mean max for the first 8 days of the month was 12.82C an anomaly of +4.62C

The anomaly for the mean minimum was even higher. Mean min to 8 Dec was 8.53C with anomaly of +5.70C

15th-22nd mean temperatures from GFS op runs for my location in rural west Hants (just south of Salisbury):

12th 12z: 10.4*C

14th 12z: 11.7*C

15th 00z: 12.2*C

That's quite an upward trend given how anomalous the values already are. This seems to be down to the milder air not being pushed away east so quickly, as the Atlantic makes less inroads against the Euro High. Typical over-progressive GFS issues?

If we then correct for the overly low nighttime minimums GFS has been producing of late, a value near 13*C looks achievable for that 8-day period. That wouldn't be a long way off three times the LTA.

The same forecast for Leeds has maxes of 11, 16, 16, 14, 17, 14, 17, 14. I doubt it'll be that mild personally but we'll see.

More remarkably it has lows of 10C and above for 5 consecutive days.

Er... Celsius temperature doesn't work that way, but I take your point! 

Your last name isn't Kelvin is it? 

Weirdly, some hints of buds on one or two trees around here. Surely not?

15.3C at Bude (Cornwall)

Looking at the list of records that Bertwhistle posted the record for today is 16.3c in Prestatyn (1982). Saturday Looks like the mostly likely record breaking day as we only have to beat 15.5c in Hemsby, Norfolk (1993).

 http://www.torro.org.uk/hightempsyear.php

Just had a look at the upper air temperatures for Thursday. I think they are colder over a lot of Sudan!

I see there are (presumably foehn assisted) 20's on the N coast of Spain now and several 18s around N Portugal.

The exceptionally mild days long progged for the 17th December and 19th December appear to now be joined by the 22nd December too. More so for the south.  Chilly over the higher ground of Scotland though.

11.5c here but cloudy and damp so doesn't feel great. 

I've been up to 15C today Kevin.

There were a few faint sunny spells early this afternoon and it felt ridiculously springlike outside. I was walking along with my light (summer) jacket open! Even accounting for the fact that I seem to feel the cold less than most, that's quite something for mid-Dec.

As usual though, there were quite a number of people walking around in winter coasts just because of the time of year. That's long puzzled me, I'd be boiling on a day like this! Speaking of which, it was way to warm in all but one of the shops I visited at lunchtime. Bah, humbug! 

Currently, it's a shade under 14*C and the sun's gone down. With thick cloud having moved in, the temp may not drop much at all tonight.

13.9c here in Bournemouth and 14.4c in Wareham.

While walking in the mountains earlier I could easily have been wearing a t-shirt and felt warm, no exaggeration. Warm, humid and no wind - it felt quite muggy.

My car thermometer recorded at 12.30 pm 17c in Twickenham.What was the official highest temp today?

I found a few sources that quote 15C for today but I don't think they're official. Heathrow got a 15.

Warmest I could find on the official list:

Hawarden 15.3 (North Wales foehn FTW!)
Heathrow and Gravesend 15.2
Yeovilton 15.1
Northolt 15.0

Looks about right.  It felt unnaturally warm out there today.  We are living through warm interesting with records falling almost on a monthly basis, I wonder why?

Nearby Kew Gardens reporting 15.3 at 12:00 today