These are CET daily mean temps in degrees Celsius for the 3 winter
months over the period 1772-2007 (2006 in the case of December).

Jan Feb Dec
1 3.29 3.92 5.11
2 3.30 3.86 5.02
3 3.18 3.99 5.05
4 3.38 3.99 5.08
5 3.23 4.07 5.14
6 3.36 4.11 4.80
7 3.18 4.23 4.59
8 3.21 3.98 4.36
9 3.35 3.93 4.17
10 3.43 3.92 4.27
11 3.28 3.80 4.18
12 3.04 3.71 4.37
13 3.28 3.63 4.49
14 3.31 3.72 4.49
15 3.19 3.97 4.39
16 3.34 3.89 4.32
17 3.34 3.74 4.42
18 3.30 3.73 4.38
19 3.44 3.76 4.06
20 3.29 3.73 3.93
21 3.48 4.14 3.94
22 3.56 4.33 3.87
23 3.50 4.45 3.82
24 3.51 4.40 3.77
25 3.39 4.48 3.44
26 3.46 4.45 3.41
27 3.62 4.59 3.41
28 3.54 4.50 3.40
29 3.72 - 3.64
30 3.79 - 3.59
31 3.96 - 3.44

I didn't bother with Feb 29th, as calculating the mean would have been
too fiddly to be worthwhile.

I've already commented on January in another post. February shows a
tendency to be a bit colder between about the 11th and 20th, giving some
credence to the Buchan cold spell (which the singularity work of Brooks
and Lamb I believe also identified). The last week is notably milder.

December shows a tendency for a relative cold period from about the 8th
to 12th. It then cools down again from about the 19th. There's no sign
of a post-Christmas mild spell, though, with the 25th to 31st being the
coldest part of the month. I suspect that the mean for the last 100
years only might show very different trends.
--
John Hall

"The covers of this book are too far apart."
Ambrose Bierce (1842-1914)

On Jan 20, 11:11*am, John Hall wrote:
These are CET daily mean temps in degrees Celsius for the 3 winter
months over the period 1772-2007 (2006 in the case of December).

* * * * Jan * * Feb * * Dec
1 * * * 3.29 * *3.92 * *5.11
2 * * * 3.30 * *3.86 * *5.02
3 * * * 3.18 * *3.99 * *5.05
4 * * * 3.38 * *3.99 * *5.08
5 * * * 3.23 * *4.07 * *5.14
6 * * * 3.36 * *4.11 * *4.80
7 * * * 3.18 * *4.23 * *4.59
8 * * * 3.21 * *3.98 * *4.36
9 * * * 3.35 * *3.93 * *4.17
10 * * *3.43 * *3.92 * *4.27
11 * * *3.28 * *3.80 * *4.18
12 * * *3.04 * *3.71 * *4.37
13 * * *3.28 * *3.63 * *4.49
14 * * *3.31 * *3.72 * *4.49
15 * * *3.19 * *3.97 * *4.39
16 * * *3.34 * *3.89 * *4.32
17 * * *3.34 * *3.74 * *4.42
18 * * *3.30 * *3.73 * *4.38
19 * * *3.44 * *3.76 * *4.06
20 * * *3.29 * *3.73 * *3.93
21 * * *3.48 * *4.14 * *3.94
22 * * *3.56 * *4.33 * *3.87
23 * * *3.50 * *4.45 * *3.82
24 * * *3.51 * *4.40 * *3.77
25 * * *3.39 * *4.48 * *3.44
26 * * *3.46 * *4.45 * *3.41
27 * * *3.62 * *4.59 * *3.41
28 * * *3.54 * *4.50 * *3.40
29 * * *3.72 * *- * * * 3.64
30 * * *3.79 * *- * * * 3.59
31 * * *3.96 * *- * * * 3.44

I didn't bother with Feb 29th, as calculating the mean would have been
too fiddly to be worthwhile.

I've already commented on January in another post. February shows a
tendency to be a bit colder between about the 11th and 20th, giving some
credence to the Buchan cold spell (which the singularity work of Brooks
and Lamb I believe also identified). The last week is notably milder.

December shows a tendency for a relative cold period from about the 8th
to 12th. It then cools down again from about the 19th. There's no sign
of a post-Christmas mild spell, though, with the 25th to 31st being the
coldest part of the month. I suspect that the mean for the last 100
years only might show very different trends.
--
John Hall

* * * * * * * * * * "The covers of this book are too far apart."
* * * * * * * * * * * * * * * * * * * Ambrose Bierce (1842-1914)

I posted my mean figures for January in the earlier 'mid Jan mild
spell' thread

Here are the figures for February ((Penzance 1992-201)
1. 9.95 5.2
2. 9.72 4.6
3. 10.03 4.7
4. 10.41 5.6
5. 10.45 5.7
6. 10.09 5.3
7. 10.55 5.4
8. 10.58 5.8
9. 10.16 5.2
10. 10.33 4.7
11. 11.33 6.4
12. 11.19 6.4
13. 10.29 5.5
14. 10.17 4.4
15. 10.57 4.1
16. 10.32 4.8
17. 10.69 4.4
18. 9.91 5.3
19. 10.08 4.8
20. 9.71 4.6
21. 10.07 3.9
22. 10.42 5.3
23. 10.50 5.7
24. 10.65 5.0
25. 10.17 4.2
26. 10.28 5.2
27. 9.80 4.6
28. 10.13 5.0

Unlike January, where there is a very distinct 'mild' spell, nothing
really clear here in the last couple of decades.

Graham
Penzance

"John Hall" wrote in message
...
These are CET daily mean temps in degrees Celsius for the 3 winter
months over the period 1772-2007 (2006 in the case of December).

Jan Feb Dec
1 3.29 3.92 5.11
2 3.30 3.86 5.02
3 3.18 3.99 5.05
4 3.38 3.99 5.08
5 3.23 4.07 5.14
6 3.36 4.11 4.80
7 3.18 4.23 4.59
8 3.21 3.98 4.36
9 3.35 3.93 4.17
10 3.43 3.92 4.27
11 3.28 3.80 4.18
12 3.04 3.71 4.37
13 3.28 3.63 4.49
14 3.31 3.72 4.49
15 3.19 3.97 4.39
16 3.34 3.89 4.32
17 3.34 3.74 4.42
18 3.30 3.73 4.38
19 3.44 3.76 4.06
20 3.29 3.73 3.93
21 3.48 4.14 3.94
22 3.56 4.33 3.87
23 3.50 4.45 3.82
24 3.51 4.40 3.77
25 3.39 4.48 3.44
26 3.46 4.45 3.41
27 3.62 4.59 3.41
28 3.54 4.50 3.40
29 3.72 - 3.64
30 3.79 - 3.59
31 3.96 - 3.44

I didn't bother with Feb 29th, as calculating the mean would have been
too fiddly to be worthwhile.

I've already commented on January in another post. February shows a
tendency to be a bit colder between about the 11th and 20th, giving some
credence to the Buchan cold spell (which the singularity work of Brooks
and Lamb I believe also identified). The last week is notably milder.

December shows a tendency for a relative cold period from about the 8th
to 12th. It then cools down again from about the 19th. There's no sign
of a post-Christmas mild spell, though, with the 25th to 31st being the
coldest part of the month. I suspect that the mean for the last 100
years only might show very different trends.
--
John Hall

"The covers of this book are too far apart."
Ambrose Bierce (1842-1914)

Thanks for these figures, John. Very interesting. What strikes me about
them though is how un-smooth they are for an average of 235 years. For
example, in the second half of February the temperature rises from 3.73 to
4.45 in just 3 days. This rather suggests that the winter temperature
profile has changed during that period, and probably several times. For
example it changed after Buchan's time, resulting in the poor fellow
getting an undeserved raspberry from the meteorological cognoscenti.

My 21-year mean temperature falls throughout December to a minimum in the
week between Christmas and the New Year, rises to the mid-January maximum,
then falls to the last week of January. It then rises to the 6th of
February, after which comes a cold period from the 8th to the 19th which, as
you say, roughly corresponds to Buchan's First Cold Spell, but overshoots it
by 5 days.

Ian Bingham,
Inchmarlo, Aberdeenshire.

"I will take mine ease at mine inn
And let the world wag."

(Unknown Elizabethan)

In article ,
Ian Bingham writes:
Thanks for these figures, John. Very interesting. What strikes me
about them though is how un-smooth they are for an average of 235
years. For example, in the second half of February the temperature
rises from 3.73 to 4.45 in just 3 days. This rather suggests that the
winter temperature profile has changed during that period, and probably
several times. For example it changed after Buchan's time, resulting
in the poor fellow getting an undeserved raspberry from the
meteorological cognoscenti.

Yes, I'm sure that there must have been changes. I'm going to try
looking at the last hundred years or so, and see what difference that
makes. (I think that a 30 year period, though fine when looking at
monthly means, would be too short for daily means, as there's a greater
possible range of daily values than there is for monthly ones.)

My 21-year mean temperature falls throughout December to a minimum in
the week between Christmas and the New Year, rises to the mid-January
maximum, then falls to the last week of January. It then rises to the
6th of February, after which comes a cold period from the 8th to the
19th which, as you say, roughly corresponds to Buchan's First Cold
Spell, but overshoots it by 5 days.

So what you see for December and February sounds broadly similar to what
I've found for the period since 1772, but very different for January.
--
John Hall

"The covers of this book are too far apart."
Ambrose Bierce (1842-1914)

On 2011-01-20 15:17:10 +0000, "Ian Bingham"
said:

"John Hall" wrote in message
...
These are CET daily mean temps in degrees Celsius for the 3 winter
months over the period 1772-2007 (2006 in the case of December).

Jan Feb Dec
1 3.29 3.92 5.11
2 3.30 3.86 5.02
3 3.18 3.99 5.05
4 3.38 3.99 5.08
5 3.23 4.07 5.14
6 3.36 4.11 4.80
7 3.18 4.23 4.59
8 3.21 3.98 4.36
9 3.35 3.93 4.17
10 3.43 3.92 4.27
11 3.28 3.80 4.18
12 3.04 3.71 4.37
13 3.28 3.63 4.49
14 3.31 3.72 4.49
15 3.19 3.97 4.39
16 3.34 3.89 4.32
17 3.34 3.74 4.42
18 3.30 3.73 4.38
19 3.44 3.76 4.06
20 3.29 3.73 3.93
21 3.48 4.14 3.94
22 3.56 4.33 3.87
23 3.50 4.45 3.82
24 3.51 4.40 3.77
25 3.39 4.48 3.44
26 3.46 4.45 3.41
27 3.62 4.59 3.41
28 3.54 4.50 3.40
29 3.72 - 3.64
30 3.79 - 3.59
31 3.96 - 3.44

I didn't bother with Feb 29th, as calculating the mean would have been
too fiddly to be worthwhile.

I've already commented on January in another post. February shows a
tendency to be a bit colder between about the 11th and 20th, giving some
credence to the Buchan cold spell (which the singularity work of Brooks
and Lamb I believe also identified). The last week is notably milder.

December shows a tendency for a relative cold period from about the 8th
to 12th. It then cools down again from about the 19th. There's no sign
of a post-Christmas mild spell, though, with the 25th to 31st being the
coldest part of the month. I suspect that the mean for the last 100
years only might show very different trends.
--
John Hall

Thanks for these figures, John. Very interesting. What strikes me
about them though is how un-smooth they are for an average of 235
years. For example, in the second half of February the temperature
rises from 3.73 to 4.45 in just 3 days. This rather suggests that the
winter temperature profile has changed during that period, and probably
several times. For example it changed after Buchan's time, resulting
in the poor fellow getting an undeserved raspberry from the
meteorological cognoscenti.

My 21-year mean temperature falls throughout December to a minimum in
the week between Christmas and the New Year, rises to the mid-January
maximum, then falls to the last week of January. It then rises to the
6th of February, after which comes a cold period from the 8th to the
19th which, as you say, roughly corresponds to Buchan's First Cold
Spell, but overshoots it by 5 days.
Ian Bingham,
Inchmarlo, Aberdeenshire.


I computed the three day running mean to even out day-to-day variation,
and plotted the running mean against winter day number (December 1 = 1,
February 27 = 89). Then as you expect you get a nice shallow U curve,
with the start of December significantly more mild than the end of
February. The trough of the curve is January 12-13, with means of 3.20
and 3.21.

There are two anomalies in the U though: a cold spell around December
10 and a warm spell around February 6.

The early December cold spell falls in a supposed Buchan warm spell,
and the February warm spell is followed by a Buchan cold spell, which
in fact isn't colder than you would expect, but is colder than the warm
spell immediately before it.

Those anomalies are still obvious if you use 5-day smoothing rather than 3-day.

Oh well. Back to work.

--

Trevor
Graphing in Lundie, in the Sidlaw Hills, 10m NW of Dundee, elev. 185m
Weather through www.trevorharley.com

In article , nospam_nov03
@jhall.co.uk says...

There's no sign
of a post-Christmas mild spell, though, with the 25th to 31st being the
coldest part of the month.


In the 80's and early 90's the post Christmas week was usually the one
where the first snowfall proper would come in. There was certainly a
good few years (10+) where it occured more often than not.

Christmas was rarely white, Hogmany rarely green.

--
Alan LeHun

In article ,
John Hall writes:
In article ,
Ian Bingham writes:
Thanks for these figures, John. Very interesting. What strikes me
about them though is how un-smooth they are for an average of 235
years. For example, in the second half of February the temperature
rises from 3.73 to 4.45 in just 3 days. This rather suggests that the
winter temperature profile has changed during that period, and probably
several times. For example it changed after Buchan's time, resulting
in the poor fellow getting an undeserved raspberry from the
meteorological cognoscenti.

Yes, I'm sure that there must have been changes. I'm going to try
looking at the last hundred years or so, and see what difference that
makes. (I think that a 30 year period, though fine when looking at
monthly means, would be too short for daily means, as there's a greater
possible range of daily values than there is for monthly ones.)

OK, here are the corresponding figures for the period from 1901, and
also the change in the means for that period with respect to those for
the whole period. (Clearly those changes would be much bigger if one
compared them with the pre-1901 period instead.)

Jan Feb Dec Jan Feb Dec
1 4.09 4.16 5.55 0.80 0.24 0.45
2 4.36 4.13 5.52 1.06 0.27 0.50
3 4.23 4.38 5.58 1.05 0.49 0.53
4 4.13 4.31 5.37 0.75 0.32 0.29
5 4.01 4.35 5.21 0.79 0.28 0.07
6 4.21 4.45 4.80 0.85 0.34 -0.01
7 3.97 4.26 4.87 0.79 0.03 0.28
8 4.17 4.25 4.82 0.96 0.27 0.45
9 4.31 3.98 4.62 0.97 0.05 0.44
10 4.40 4.06 4.73 0.98 0.14 0.47
11 4.21 3.89 4.77 0.93 0.09 0.58
12 3.84 3.78 4.72 0.79 0.07 0.35
13 3.76 3.58 4.84 0.48 -0.04 0.35
14 3.73 3.35 4.89 0.42 -0.37 0.40
15 3.96 3.74 4.66 0.77 -0.23 0.27
16 3.95 3.80 4.68 0.61 -0.09 0.36
17 3.76 3.72 4.79 0.43 -0.01 0.37
18 3.79 3.80 4.55 0.49 0.07 0.17
19 3.94 3.98 4.21 0.5 0.23 0.16
20 3.94 3.95 4.12 0.65 0.22 0.18
21 4.05 4.17 4.21 0.58 0.03 0.27
22 3.93 4.29 4.44 0.37 -0.04 0.57
23 3.72 4.40 4.67 0.22 -0.05 0.85
24 3.80 4.22 4.49 0.29 -0.17 0.72
25 3.75 4.16 4.24 0.36 -0.32 0.80
26 3.73 4.38 4.26 0.27 -0.07 0.85
27 3.76 4.58 4.29 0.14 -0.01 0.87
28 3.80 4.69 4.21 0.26 0.09 0.81
29 4.00 - 4.13 0.28 - 0.49
30 4.00 - 4.14 0.20 - 0.55
31 4.13 - 4.07 0.17 - 0.63

Early January has warmed by much more than late January. The period from
the 12th to the 28th is now the coldest, with a brief warmer spell from
the 19th-22nd. The 1st-11th is the warmest part of the month. So the
recent phenomenon of mid-January being milder than early or late January
is still not apparent in these figures.

February has warmed up by much less than the other winter months (some
periods even having cooled), showing a strenthening of the trend
established in late January. I wonder if that could be because
easterlies have perhaps warmed up less than northerlies (where less
Arctic sea ice compared to the 18th and 19th centuries could be a
factor); prolonged easterlies are much more common in late winter than
in early winter. The coldest period is from the 9th to the 20th, ie much
the same as before. That period is now comparable in coldness to the
coldest part of January, which used not to be the case. Indeed
Valentine's Day is now on average easily the coldest day of the winter!

December has also warmed substantially, though not as much as January,
and especially from about the 23rd onwards. The end of the month is
still the coldest period, though by less than before. There's still no
sign of a post-Christmas warming. Indeed the 22nd-24th is on average
warmer than the following days.

It's noteworthy that 4 of the 8 sub-zero CET Februaries have occurred
since 1901 (all since 1947), compared with only 3 of 20 sub-zero
Januaries (and now 1 of 7 sub-zero Decembers), which is consistent with
the trends identified above.
--
John Hall

"The covers of this book are too far apart."
Ambrose Bierce (1842-1914)

"John Hall" wrote in message
...
In article ,
John Hall writes:
In article ,
Ian Bingham writes:
Thanks for these figures, John. Very interesting. What strikes me
about them though is how un-smooth they are for an average of 235
years. For example, in the second half of February the temperature
rises from 3.73 to 4.45 in just 3 days. This rather suggests that the
winter temperature profile has changed during that period, and probably
several times. For example it changed after Buchan's time, resulting
in the poor fellow getting an undeserved raspberry from the
meteorological cognoscenti.

Yes, I'm sure that there must have been changes. I'm going to try
looking at the last hundred years or so, and see what difference that
makes. (I think that a 30 year period, though fine when looking at
monthly means, would be too short for daily means, as there's a greater
possible range of daily values than there is for monthly ones.)

OK, here are the corresponding figures for the period from 1901, and
also the change in the means for that period with respect to those for
the whole period. (Clearly those changes would be much bigger if one
compared them with the pre-1901 period instead.)

Jan Feb Dec Jan Feb Dec
1 4.09 4.16 5.55 0.80 0.24 0.45
2 4.36 4.13 5.52 1.06 0.27 0.50
3 4.23 4.38 5.58 1.05 0.49 0.53
4 4.13 4.31 5.37 0.75 0.32 0.29
5 4.01 4.35 5.21 0.79 0.28 0.07
6 4.21 4.45 4.80 0.85 0.34 -0.01
7 3.97 4.26 4.87 0.79 0.03 0.28
8 4.17 4.25 4.82 0.96 0.27 0.45
9 4.31 3.98 4.62 0.97 0.05 0.44
10 4.40 4.06 4.73 0.98 0.14 0.47
11 4.21 3.89 4.77 0.93 0.09 0.58
12 3.84 3.78 4.72 0.79 0.07 0.35
13 3.76 3.58 4.84 0.48 -0.04 0.35
14 3.73 3.35 4.89 0.42 -0.37 0.40
15 3.96 3.74 4.66 0.77 -0.23 0.27
16 3.95 3.80 4.68 0.61 -0.09 0.36
17 3.76 3.72 4.79 0.43 -0.01 0.37
18 3.79 3.80 4.55 0.49 0.07 0.17
19 3.94 3.98 4.21 0.5 0.23 0.16
20 3.94 3.95 4.12 0.65 0.22 0.18
21 4.05 4.17 4.21 0.58 0.03 0.27
22 3.93 4.29 4.44 0.37 -0.04 0.57
23 3.72 4.40 4.67 0.22 -0.05 0.85
24 3.80 4.22 4.49 0.29 -0.17 0.72
25 3.75 4.16 4.24 0.36 -0.32 0.80
26 3.73 4.38 4.26 0.27 -0.07 0.85
27 3.76 4.58 4.29 0.14 -0.01 0.87
28 3.80 4.69 4.21 0.26 0.09 0.81
29 4.00 - 4.13 0.28 - 0.49
30 4.00 - 4.14 0.20 - 0.55
31 4.13 - 4.07 0.17 - 0.63

Early January has warmed by much more than late January. The period from
the 12th to the 28th is now the coldest, with a brief warmer spell from
the 19th-22nd. The 1st-11th is the warmest part of the month. So the
recent phenomenon of mid-January being milder than early or late January
is still not apparent in these figures.

February has warmed up by much less than the other winter months (some
periods even having cooled), showing a strenthening of the trend
established in late January. I wonder if that could be because
easterlies have perhaps warmed up less than northerlies (where less
Arctic sea ice compared to the 18th and 19th centuries could be a
factor); prolonged easterlies are much more common in late winter than
in early winter. The coldest period is from the 9th to the 20th, ie much
the same as before. That period is now comparable in coldness to the
coldest part of January, which used not to be the case. Indeed
Valentine's Day is now on average easily the coldest day of the winter!

December has also warmed substantially, though not as much as January,
and especially from about the 23rd onwards. The end of the month is
still the coldest period, though by less than before. There's still no
sign of a post-Christmas warming. Indeed the 22nd-24th is on average
warmer than the following days.

It's noteworthy that 4 of the 8 sub-zero CET Februaries have occurred
since 1901 (all since 1947), compared with only 3 of 20 sub-zero
Januaries (and now 1 of 7 sub-zero Decembers), which is consistent with
the trends identified above.
--
John Hall

"The covers of this book are too far apart."
Ambrose Bierce (1842-1914)

Thanks John. Again, very interesting. I'm going to have to mull all this
over but I can see straight away that the January figures you've just given
are almost a mirror-image of mine for 1990-2010. So the mid-January
mildening we're now experiencing is a relatively recent phenomenon - it
would be interesting to know how recent. But how long these cycles are and
why they take place is a whole new ballgame!

Ian Bingham,
Inchmarlo, Aberdeenshire.

You may also be interested in the Wokingham daily means for 1976 to 2005,
which can be found in graphical form at:
http://www.woksat.info/wwp/graav7605.gif

--
Bernard Burton

Wokingham Berkshire.

Weather data and satellite images at:
www.woksat.info/wwp.html

"John Hall" wrote in message
...
These are CET daily mean temps in degrees Celsius for the 3 winter
months over the period 1772-2007 (2006 in the case of December).

Jan Feb Dec
1 3.29 3.92 5.11
2 3.30 3.86 5.02
3 3.18 3.99 5.05
4 3.38 3.99 5.08
5 3.23 4.07 5.14
6 3.36 4.11 4.80
7 3.18 4.23 4.59
8 3.21 3.98 4.36
9 3.35 3.93 4.17
10 3.43 3.92 4.27
11 3.28 3.80 4.18
12 3.04 3.71 4.37
13 3.28 3.63 4.49
14 3.31 3.72 4.49
15 3.19 3.97 4.39
16 3.34 3.89 4.32
17 3.34 3.74 4.42
18 3.30 3.73 4.38
19 3.44 3.76 4.06
20 3.29 3.73 3.93
21 3.48 4.14 3.94
22 3.56 4.33 3.87
23 3.50 4.45 3.82
24 3.51 4.40 3.77
25 3.39 4.48 3.44
26 3.46 4.45 3.41
27 3.62 4.59 3.41
28 3.54 4.50 3.40
29 3.72 - 3.64
30 3.79 - 3.59
31 3.96 - 3.44

I didn't bother with Feb 29th, as calculating the mean would have been
too fiddly to be worthwhile.

I've already commented on January in another post. February shows a
tendency to be a bit colder between about the 11th and 20th, giving some
credence to the Buchan cold spell (which the singularity work of Brooks
and Lamb I believe also identified). The last week is notably milder.

December shows a tendency for a relative cold period from about the 8th
to 12th. It then cools down again from about the 19th. There's no sign
of a post-Christmas mild spell, though, with the 25th to 31st being the
coldest part of the month. I suspect that the mean for the last 100
years only might show very different trends.
--
John Hall

"The covers of this book are too far apart."
Ambrose Bierce (1842-1914)

In article ,
Bernard Burton writes:
You may also be interested in the Wokingham daily means for 1976 to 2005,
which can be found in graphical form at:
http://www.woksat.info/wwp/graav7605.gif

Thanks, Bernard. The graph for the three winter months seems to agree
pretty well with what I've found, suggesting that the mid-January
warming that others have found in their records is probably a very
recent development.
--
John Hall

"The covers of this book are too far apart."
Ambrose Bierce (1842-1914)