December CET

[Beazle]

Manley (Eden) CET to the 30th is minus 0.7 C.

[The PIT]

It'll be a close run thing for this December to beat 1981 here thanks to this current mild spell.

One thing for certain, it will the driest December on my records at this site. The rainfall total currently stands at 40.1mm and the record is 54.0 mm in 2004; it will probably be the driest December since 1971 when I recorded just over 28 mm at a lower site about 15km away.

Won't do it here. 99% sure Sheffield will come in at 0.4C. Two mild spells being the killer. One mid month and another at the end. The mild spells were mainly at night when the temperature hardly shifted from the day time values. Being on hill also prevented some more extreme night time lows which is another factor.

[Optimus Prime]

Obviously a mean of 0.4c is still exceptional though. Equates to about 0.0c for an average January or February.

Edited December 31, 2010 by Optimus Prime

[Kentish Man]

Hadley in at - 0.4C today (Dec 1 - 30)

[reef]

Its looking quite likely now that the finishing number before adjustments will be -0.2C. That would still make it the joint 6th coldest December on record and half a degree lower than 1981. We'd then require a 0.3C adjustment downwards to equal the second coldest on record.

Its a shame the record isnt going but its still remarkable that even without adjustments it could be the joint 31st coldest month ever and joint 7th coldest in the last 105 years!

[Isolated Frost]

-0.3C likely to the 31st (-0.2C at a push).

Looks like second coldest since Daily Means is near enough certain (-0.3C) after adjustments.

Some very cool nights at the start of the month, plus the Front moving on the 16th could mean some adjustments.

-0.4C to -0.6C looks like the landing range now.

[reef]

-0.3C likely to the 31st (-0.2C at a push).

Looks like second coldest since Daily Means is near enough certain (-0.3C) after adjustments.

Some very cool nights at the start of the month, plus the Front moving on the 16th could mean some adjustments.

-0.4C to -0.6C looks like the landing range now.

A mean of 5.2C on tomorrow's update will make it -0.2C. The min on today's update is 4.0C so a max of less than 6.4C is required to remain on -0.3C. It'll be close.

[Paul T]

Lets have a little look at this then,

The combined value of the cet is now -12.9, this divided by the days (30 so far) gives an average cet mean, as Kentish man above says, of -0.43.

The min for the 31st is 4oC, and i believe the max will be close to 5.8, so the final mean figure will be 4.9oC. This will rise the 'total' CET value to -8.0, divided by 31 days = finished place at -0.26 (rounded to -0.3).

If the mean of the 31st comes in at 5.2 or more then the finishing CET will be -0.2oC.

Looking back at this years adjustments; the average month end ''adjustment'' has knocked off -0.24oC of the estimated finishing total. I would imagine Dec adjustment will be around-0.05 to -0.15.

This would then possibly give us the Third coldest Dec (including the early rounded recordings) since 1659.

Paul

[Isolated Frost]

Lets have a little look at this then,

The combined value of the cet is now -12.9, this divided by the days (30 so far) gives an average cet mean, as Kentish man above says, of -0.43.

The min for the 31st is 4oC, and i believe the max will be close to 5.8, so the final mean figure will be 4.9oC. This will rise the 'total' CET value to -8.0, divided by 31 days = finished place at -0.26 (rounded to -0.3).

If the mean of the 31st comes in at 5.2 or more then the finishing CET will be -0.2oC.

Looking back at this years adjustments; the average month end ''adjustment'' has knocked off -0.24oC of the estimated finishing total. I would imagine Dec adjustment will be around-0.05 to -0.15.

This would then possibly give us the Third coldest Dec (including the early rounded recordings) since 1659.

Paul

With cold nights, I'm sure the adjustment would be over 0.05C to 0.15C. I'd imagine it would be closer to 0.2C to the 0.3C.

I'd say -0.4C to -0.5C.

I wouldn't use the roundings before 1723 because I'd say it's vague, so IMO it'll be the second coldest.

_________________________________________________________________________________________

The Three Stations (Hadley's):

Rothamstead is at 5.1C (which is the current max).

5.6C at Stonyhurst (also the max).

Pershore is also at 5.6C (which yet again, is the daily max).

-0.3C before adjustments looks most likely currently, -0.5C is the best bet I think.

Percentages (AFTER ADJUSTMENTS):

Over -0.3C: 1%

-0.3C: 10%

-0.4C: 30%

-0.5C: 39%

-0.6C: 15%

-0.7C: 4%

Under -0.7C: 1%

[Optimus Prime]

More than 4% chance for being at -0.7c I would had thought? More like 30% given Manleys current temperature.

[Isolated Frost]

Hadley should probably come out 0.1C/0.2C higher. I'd say Manley's moving to -0.6C today aswell.

[Optimus Prime]

Yeah seems Hadley is coming in below Manley quite often these days. Was once rare.

Edited December 31, 2010 by Optimus Prime

[Thundery wintry showers]

Here at Cleadon I managed to record a sub zero December (only just, at -0.1C)- which is more remarkable than the CET being below zero because it is more rare for North Sea areas to get a monthly mean below zero due to the tempering effects of the sea when north and east winds dominate. Although we don't look like getting a record low CET, some parts of the country could well have had their coldest December for over 350 years, particularly in northern and western regions.

Looking at the evidence above I am expecting the Hadley version to come out at -0.3 or -0.4 after adjustments, and Manley to come out at -0.6, so at least no arguments as to whether the record goes or not.

[casparjack]

My monthly mean here in Herefordshire will come out at exactly -1.0c, average max 1.4c and average minimum -4.0c - this might drop a little as the temperature is now falling again, we stand at 23 air frosts and 30 ground frosts so far, today being the only day without a ground frost so far, so fingers crossed for a clear spell or two before midnight to achieve 100%...

Also 14 ice days, 12 nights sub -5.0c and 5 below -10.0c - exceptional.

[weatherguy]

Here's what Skynews (may not be reliable from there I know lol) are saying on the matter...

"According to the Central England Temperature, which is used as a benchmark, the average temperature in December was -0.6C - the lowest since 1890."

http://news.sky.com/skynews/Home/UK-News/Weather-December-2010-Was-Coldest-December-In-120-Years-Meteorologists-Say/Article/201012415875406?lpos=UK_News_Carousel_Region_3&lid=ARTICLE_15875406_Weather:_December_2010_Was_Coldest_December_In_120_Years,_Meteorologists_Say

Is this right?

[Summer of 95]

Heard on the radio on Friday morning that December averaged -0.6; that's about halfway between what I expected for Manley and Hadley (-0.8 and -0.4ish respectively).

Whether it beat 1890 or not, I've now banished one of my ghosts; I've always rued the fact that I can't remember anything of December 1981 (though my absolute earliest memory is a street party for the royal wedding that summer, my earliest weather memory is July 1983)- but that doesn't matter because I've lived through and can remember a colder December. And a colder December that my great-grandmother (who lived from 1893-1991) ever knew.

Edited January 1, 2011 by Summer of 95

[Weather-history]

The coldest months for Manchester since 1890

Feb 1895: -1.7

Feb 1947: -1.4

Jan 1963: -1.4

Jan 1940: -0.8

Dec 2010: -0.6

Jan 1945: -0.1

Feb 1986: -0.1

Dec 1890: 0.0

Feb 1963: 0.0

Feb 1942: 0.2

Jan 1979: 0.3

Feb 1956: 0.4

Dec 1950: 0.5

Dec 1981: 0.7

Edited January 1, 2011 by Mr_Data

[I remember Atlantic 252]

My monthly mean was -1.1C, avg max 1.6C, avg min -3.8C, 14 ice days

Highest max, 7.8C on the 11th

highest min, 3.5C on the 30th

lowest max, -5.1C on Xmas day

lowest min, -11.6C 0n Xmas day

[Paul T]

Its great seeing all the stats guys, thanks.

WOW, what an adjustment!

The estimated CET finished at -0.25 oC, but with adjustments it was:

-0.7 oC!!

Second coldest on record!

The week of the 18th - 24th must be up there with the coldest; averaging -4.3oC.

http://hadobs.metoffice.com/hadcet/cet_mean_2010

[Snowly does it]

Final figure -0.7, second coldest on record and just missing the coldest.

Annual figure 8.83

[Paul T]

The CET Min value for Dec is -3.8oC.

This is -1.1oC colder than any other Dec CET month, quite unbelievable to be frank.

http://hadobs.metoffice.com/hadcet/mly_cet_min_sort.txt

[Weather-history]

4th coldest November-December CET combination on record

November-December

1676: 1.5

1878: 1.6

1796: 2.15

2010: 2.25

[Isolated Frost]

Told Ya's there would be an adjustment.

I thought along the lines of -0.3C, but -0.45C?!

Brilliant month, most certainly the Coldest EVER December for parts of E Scotland and E England...

[Isolated Frost]

Now Now Now... what will Eden come out with? Could this be controversial?

-0.7C from Hadley.

Coldest Months in the CET Zone (1772-2010)

1. January 1795: -3.1C

2. January 1814: -2.9C

3. January 1963: -2.1C

4. February 1947: -1.9C

5. February 1895: -1.8C

6. February 1855: -1.7C

7. January 1776: -1.6C

8. January 1838: -1.5C

= January 1881: -1.5C

9. January 1940: -1.4C

10. February 1986: -1.1C

11. January 1780: -0.8C

= December 1890: -0.8C

12. January 1879: -0.7C

= February 1963: -0.7C

= December 2010: -0.7C

Only 13 Months have ever been colder in 238 years.

The first of this millenium...

...and the coldest in 24 years.

As cold as February 63'...

...and 1C colder than December 81'.

Historic, Truly Historic. If we get another one in the next 30 years, we will be very, very lucky. Cherish this month...

Edited January 1, 2011 by reef
Paragraphs please, some people cant read your posts when they have such huge spaces

[reef]

2nd coldest December on record

22nd coldest month ever

joint 5th coldest month of the last 115 years

I dont think anyone in their wildest dreams could have expected a month like that. What an exceptional December!