Comparing February averages
 

I had an odd thought just now: suppose this year was a leap year - what
would the mean temperature for February be?

The mean temperature for the 1st March was -0.5C - adding this to
February's temperatures as though it was the 29th February brings the
February mean down by 0.2C. As February was 0.1C above the eLTA, that
would be the difference between a slightly above average month and a
slightly below average month temperature-wise.

Then I thought: but the end of February is quite often cold. So does the
leap-year effect show up? Are there statistically more cold Februaries
attributed to leap-years than other years?

I might be wrong, but as least it might provide someone with a few
interesting minutes to find out ;)

--
Jonathan Stott
Canterbury Weather: http://www.canterburyweather.co.uk/
Reverse my e-mail address to reply by e-mail

Comparing February averages
 

In article ,
Jonathan Stott writes:
I had an odd thought just now: suppose this year was a leap year - what
would the mean temperature for February be?

The mean temperature for the 1st March was -0.5C - adding this to
February's temperatures as though it was the 29th February brings the
February mean down by 0.2C. As February was 0.1C above the eLTA, that
would be the difference between a slightly above average month and a
slightly below average month temperature-wise.

Then I thought: but the end of February is quite often cold. So does
the leap-year effect show up? Are there statistically more cold
Februaries attributed to leap-years than other years?

I might be wrong, but as least it might provide someone with a few
interesting minutes to find out ;)


I would have thought that on average Leap Year Februaries would be
warmer, in that being at the end of the month the 29th would be more
likely to be above the average for 1st-28th than below it. But the
average effect would be very small, so I doubt would be discernible.
--
John Hall
"Three o'clock is always too late or too early
for anything you want to do."
Jean-Paul Sartre (1905-1980)

Comparing February averages
 

Felly sgrifennodd John Hall :
In article ,
I would have thought that on average Leap Year Februaries would be
warmer, in that being at the end of the month the 29th would be more
likely to be above the average for 1st-28th than below it. But the
average effect would be very small, so I doubt would be discernible.

Because a leap-year is a re-adjustment of our calendar to keep it in synch
with the earth's rotation around the sun, a leap year February 1st is
earlier in the (astronomical) year than any other February 1st, so might
be statistically cooler. This would presumably outweigh the effect you
suggest above.

One might try to make a case for the year after a leap year having a
milder February (or for that matter any spring month), and the one before
having a cooler February, but the difference from the mean astronomical
time is only around 12 hours, so I guess won't be noticeable.

Adrian
--
Adrian Shaw ais@
Adran Cyfrifiadureg, Prifysgol Cymru, aber.
Aberystwyth, Ceredigion, Cymru ac.
http://users.aber.ac.uk/ais uk

Comparing February averages
 

"Jonathan Stott" wrote in message
...
I had an odd thought just now: suppose this year was a leap year - what
would the mean temperature for February be?

The mean temperature for the 1st March was -0.5C - adding this to
February's temperatures as though it was the 29th February brings the
February mean down by 0.2C. As February was 0.1C above the eLTA, that
would be the difference between a slightly above average month and a
slightly below average month temperature-wise.

Then I thought: but the end of February is quite often cold. So does the
leap-year effect show up? Are there statistically more cold Februaries
attributed to leap-years than other years?

I might be wrong, but as least it might provide someone with a few
interesting minutes to find out ;)

That is an interesting point but John and Adrian seem to think the
effect is small.

There is a similar problem that I have identified with 30 year
averages. One of the main drivers of climate is the 22 year
solar cycle. But if you compare two consecutive 30 year averages
one will contain three solar maximums and two solar minimums,
whereas the other will contain two maximums and three minimums.

Thus the two 30 year averages are not directly comparable. Does
anyone know if this has been pointed out before, and is it taken
into account when producing climate data?

Cheers, Alastair.

Comparing February averages
 

"Jonathan Stott" wrote in message
...
I had an odd thought just now: suppose this year was a leap year - what
would the mean temperature for February be?

The mean temperature for the 1st March was -0.5C - adding this to
February's temperatures as though it was the 29th February brings the
February mean down by 0.2C. As February was 0.1C above the eLTA, that
would be the difference between a slightly above average month and a
slightly below average month temperature-wise.

Then I thought: but the end of February is quite often cold. So does the
leap-year effect show up? Are there statistically more cold Februaries
attributed to leap-years than other years?

I might be wrong, but as least it might provide someone with a few
interesting minutes to find out ;)

February is of course one of the driest months of the year but this
is helped by it (usually) being up to 10% shorter than other months.

Col
--
Bolton, Lancashire.
160m asl.