Yes. I would make the average temperature for the day of 27.5 C “knowing” that I have 24 hourly readings throughout the day. This is obviously impractical on a lot of stations.

“”John S. (10:26:20) :

Some commenters here are forgetting that:

a) US practice is to take (MAX+MIN)/2 as the “average” temperature.

b) The temperature at the time of reading MAX/MIN instruments is not material to that average.”"

That would give 25.0 C for the days reading. Quite a difference.

If you consider the UHI effect around the stations as portrayed by Anthony’s survey I feel it is quite possible that the “MAX” temperature may only apply over a brief time, whilst the rest of the time the temperature is closer to the “MIN”.

Consider 1 hour at 30C and 23 hours at 20C would give an “average” of 20.4C with 24 hourly readings. Rather less than the “practice” reading of 25C that would result.

The practice of (MAX+MIN)/2 as the “average” temperature is simply not a true data reading for the whole day.

Brilliant! Those original temps went down quite a bit, huh? No wonder there is an alarming warming trend.

…

1) What graph plots the actual UNADJUSTED temperatures (temperature differences from so-called 0.0 reference point) at this site?

2) Do we have any (5, 10, 20, 70, or 270) sites that can reasonably be claimed to NOT have gained a UHI effect over the years? Regardless of anything else, of any other changes in local siting, thermometers, or change in postmasters doddering outside to record the weatehr at 6:00 AM or 9:00 PM?

a) US practice is to take (MAX+MIN)/2 as the “average” temperature.

b) The temperature at the time of reading MAX/MIN instruments is not material to that average.

My local weather seems to be monitored automatically. The station is on the mast at the pier head just behind the floodlights. What will happen when the lights are switched on I don’t know. Must make a note next time and check the data page.
See link below for picture:

http://www.milfordweather.org.uk/
”

And what about the hot car engine directly beneath – un freaking believable!!
Is that a temp sensor right behind the flood lights?
If so that is very damning?

cheers David

When Global Warming proponents say the “World is getting warmer!”, what temperature are they referring to? Are they using these temperature trends? Atmospheric trends? Sea Surface Temperatures?

(Or, what I suspect, the one which shows that temperature is rising at any given time?)

And another question:

At what point does a ‘weather temperature trend’ become a ‘climate temperature trend’? 5 years? 10 years? 30 years? 100 years?

http://www.milfordweather.org.uk/

And this link for current monthly data;

http://www.milfordweather.org.uk/atmos_month.php

Exactly. Time of observation adjustments are made up data. Basically you take a min/max reading which says “the min and max for the 24 hour period before 6pm was x/y” and somehow “adjust” it to magically divine what the min/max would have been if measured at midnight. That’s not data – as you say, it’s a guess.

Like RichardsIII, I am also confused by TOBS adjustments. The early thermometers gave a mechanical max-min, the later ones give an electronic max-min. Where is the difference?

As long as the readings are consistently 24 hours apart, and not taken at midday or midnight, does it really mater what time of day the readings are taken? Surely any minor differences in readings would cancel out over time, rather than leading to a 2oc difference.

Any “adjustment” to define the day’s “maximum” temperature after taking a reading at say 5:00pm in the afternoon is just a guess, surely?

The same applies to guessing the night time (early dawn) minimum daily temperature.

Having a bit of a heat wave here in the U.K.: we had 32oC somewhere today, the first time we’ve had >30 in 3 years. It looks like the heat wave will last until the end of the week, tailing off by sunday, when 18C and rain is forecast…”

To be more accurate it’s only a heatwave in London. Rest of the country has been much lower.
cheers David

More accurately, by microsite violations.

Oh, that debate. Saw the video. The audience didn’t buy it, and the moderator didn’t allow any questions other than kissing up to the AGW proponents.
It was terribly insulting to the public in general.