Mean Temperatures
Forum rules
These topics are a read-only archive and may be subject to out-of-date information.
For today's weather discussion head to: New Zealand Weather & Climate
These topics are a read-only archive and may be subject to out-of-date information.
For today's weather discussion head to: New Zealand Weather & Climate
- NZstorm
- Posts: 11333
- Joined: Mon 10/03/2003 19:38
- Location: Grey Lynn, Auckland
- Has thanked: 342 times
- Been thanked: 361 times
Mean Temperatures
How are mean temperatures computed these days? The traditional method is to Max + Min /2.
Just wondering whether the likes of NIWA have adopted a new method or not.
Just wondering whether the likes of NIWA have adopted a new method or not.
- David
- Posts: 7589
- Joined: Sat 18/08/2007 21:02
- Location: Howick, Auckland
- Has thanked: 423 times
- Been thanked: 832 times
- Contact:
Re: Mean Temperatures
I always use the traditional method but I notice some online weather stations average the temperature at many points of the day to give the days mean. Not to say these stations are necessarily using meteorological standards though.
Just sent an email to Jim Salinger asking this question, hopefully he can find the time to answer.
Just sent an email to Jim Salinger asking this question, hopefully he can find the time to answer.
-
- Posts: 3745
- Joined: Sat 24/01/2004 16:56
- Location: Wellington
- Has thanked: 188 times
- Been thanked: 123 times
Re: Mean Temperatures
It's still common for summarised reports to use (max+min)/2. The point is that if a consistent formula is used then trends and anomalies can still be assessed. Met Service many years ago drew up a table of monthly adjustments which could be applied to a small set of stations studied (about a dozen) to convert this measure to a mean based on hourly values averaged, or something like that.
- David
- Posts: 7589
- Joined: Sat 18/08/2007 21:02
- Location: Howick, Auckland
- Has thanked: 423 times
- Been thanked: 832 times
- Contact:
Re: Mean Temperatures
Just wondering if any else in Auckland with soil thermometers could help me. My soil reading now is 18.7C, but I find that a bit strange for September. All other days in the last week the readings have been between 15-18C. Does this sound right?
-
- Posts: 339
- Joined: Sun 12/08/2007 15:48
- Location: Invercargill / Dunedin / Queenstown
- Has thanked: 0
- Been thanked: 0
Re: Mean Temperatures
What do people here think about max + min / 2? Do you think this is sufficient? Especially for examining trends? Or would a mean or median of regular sample points be better? Could be an interesting project for a climatology/stats/geography student...
Obviously you can't really go changing standards if you want to use long records for data analysis, but all the same...
Obviously you can't really go changing standards if you want to use long records for data analysis, but all the same...
-
- Posts: 9933
- Joined: Sun 29/06/2003 22:39
- Location: Mt Eden Auckland
- Has thanked: 870 times
- Been thanked: 880 times
Re: Mean Temperatures
If you have warm NW for an hour followed by cold southerly for 23 hours, would the average temp be a good reflection of the day ?What do people here think about max + min / 2?
Also with higher dewpoint conditions over northern NZ temps tend to stay closer to the max longer as moist air is slower to release warmth.
- NZstorm
- Posts: 11333
- Joined: Mon 10/03/2003 19:38
- Location: Grey Lynn, Auckland
- Has thanked: 342 times
- Been thanked: 361 times
Re: Mean Temperatures
Yes, the 'traditional mean' has its weaknesses but I think for most days it works okay.
I would expect NIWA to be now developing/employing a finer model for future use.
I would expect NIWA to be now developing/employing a finer model for future use.
-
- Posts: 18531
- Joined: Wed 12/03/2003 22:08
- Location: Raukapuka Geraldine
- Has thanked: 1781 times
- Been thanked: 1429 times
Re: Mean Temperatures
I don't want to be silly or ask a stupid question, but what is the difference betwixt man and average temperature?
Is it the same formula?
JohnGaul
NZTS
Is it the same formula?
JohnGaul
NZTS
JohnGaul
NZThS
NZThS
- David
- Posts: 7589
- Joined: Sat 18/08/2007 21:02
- Location: Howick, Auckland
- Has thanked: 423 times
- Been thanked: 832 times
- Contact:
Re: Mean Temperatures
By average they are referring to mean, so they are the same thingNZ Thunderstorm Soc wrote:I don't want to be silly or ask a stupid question, but what is the difference betwixt man and average temperature?
Is it the same formula?
-
- Posts: 18531
- Joined: Wed 12/03/2003 22:08
- Location: Raukapuka Geraldine
- Has thanked: 1781 times
- Been thanked: 1429 times
Re: Mean Temperatures
OK then. I meant mean not manDavid wrote:By average they are referring to mean, so they are the same thingNZ Thunderstorm Soc wrote:I don't want to be silly or ask a stupid question, but what is the difference betwixt man and average temperature?
Is it the same formula?
JohnGaul
NZTS
JohnGaul
NZThS
NZThS
- David
- Posts: 7589
- Joined: Sat 18/08/2007 21:02
- Location: Howick, Auckland
- Has thanked: 423 times
- Been thanked: 832 times
- Contact:
Re: Mean Temperatures
My email to J. Salinger of niwa:
> It has been brought up on the NZ weather forum how daily mean temps are
> recorded by metservice/niwa. Is the traditional method still used
> (max+min)/2 or is some other method used now?
His response:
You are correct - the (max+min)/2 is used. This has been used since
climate records began during the 19th century.
That solves the matter then
> It has been brought up on the NZ weather forum how daily mean temps are
> recorded by metservice/niwa. Is the traditional method still used
> (max+min)/2 or is some other method used now?
His response:
You are correct - the (max+min)/2 is used. This has been used since
climate records began during the 19th century.
That solves the matter then
- David
- Posts: 7589
- Joined: Sat 18/08/2007 21:02
- Location: Howick, Auckland
- Has thanked: 423 times
- Been thanked: 832 times
- Contact:
Re: Mean Temperatures
http://www.niwascience.co.nz/__data/ass ... mp_650.jpg
This is interesting - one area had its warmest July to September period on record.
This is interesting - one area had its warmest July to September period on record.