The recent record temperature at Heathrow

[Terminal Moraine]

Anyone any idea what these official stations do to calibrate their thermometers and how often it is performed?

The thermometers are checked against the Met Office inspector's thermometer which is calibrated by the National Physics Laboratory every few months ( I think it's every 6 months but can't be certain as it's some time since I was told)

Met Office stations are inspected every 3 years but I'm not sure if major stations such as Heathrow are inspected more frequently.

[johnholmes]

Neither can I remember TM how often full Met stations were checked/inspected. Certainly not longer than every 3 years. The relevant NPL thermometers would arrive and a month long check every hour 24x7 would then be carried out. The average of any difference was then applied to the station thermometers. If they differed by more then, I think, 0.3C, then they had to be returned and newly calibrated ones were sent to replace them. So very stringent checks were made on operational offices. Climatological stations were checked in a similar fashion, obviously not 24x7 nor am I sure how often.

[Daniel*]

IMBY it reached 36.0C I do not find the temperature recorded @Heathrow on that day dubious at all?

Edited July 18, 2015 by Daniel*

[4wd]

Whichever way the wind blows it ain't over green fields.

[Methuselah]

Whichever way the wind blows it ain't over green fields.

Hasn't it been like that for about fifty years? 

[cheeky_monkey]

IMBY it reached 36.0C I do not find the temperature recorded @Heathrow on that day dubious at all?

Ditto it reached 36c where I live which is 10miles from Heathrow as the crow flies or an airplane for that matter...so do not see what all the fuss is about?

[keithlucky]

More rubbish spouted about record temperature recorded at Heathrow according to met own data only 35.9 c was reached at 3pm and declined at 4pm,or did the record temperatures occur when  a Jumbo jet flew past ?

Enough said on this moment of climate hysteria from the met office subject put to bed ,http://t.co/3GCHf1koVL

Edited July 20, 2015 by keithlucky

[Captain Shortwave]

It reached 34C that day at my place of work (Chatteris), the nearest metoffice station at Wittering recorded its highest ever temperature that day of 35.3C, beating the 35.2C reached in August 1998.

I can't see any issues really, there was always going to be variation between stations, for no reason other than there was quite a lot of high level cloud which meant some places missed out of the highest temperatures. Writtle for example only reached a high of 31C, despite this temperature being reached before midday. Cloud being the issue, other nearby stations hit 34C.

Enough maxima of 34/35C were recorded that day over a widespread area to suggest that the high recorded at Heathrow would be valid. As Pete say the station and the runway has been there for many many years, why hasn't Heathrow taken the record before this point?

 

Also it seems the only people banging on about climate seem to be those who deny it anyway, can an extreme event happen due to a series of variables coming together at the right time to produce the perfect set up to break the temperature record. The pulse of heat was the strongest we have seen since the heatwave of August 2003, the temperatures on that day came after 30C was reached the previous day in the south east and many days prior to that had reached the mid to high twenties. I have no problem believing that the record went, but it is only an isolated event based on a perfect synoptic set up, just like halloween last year.

Edited July 20, 2015 by Captain shortwave

[richie3846]

I know a lot has already been said on this subject but this is why I am sure the reading was valid:

 

I live in Swindon, not too far from Heathrow really (I guess around 80 miles). By 9am temperatures were rocketing into the high 20s already. I already knew by then that perfect conditions could smash the Swindon (Lyneham) record of around 35c. All time record not July record. We ended up on about 32c. What stuffed it up for us, was that there was a great big bank of cloud around 1030-1230, followed by other smatterings of cloud throughout the afternoon. Despite the cloud, we still has the warmest temps since '06. We only had around 10 hours of sun I reckon, so a full 15 hours or so would have smashed that record.

 

In addition, you could argue that town temperatures are what people actually feel. The Lyneham station is rural, exposed, on a hill. Swindon itself in a valley,10 miles further east, urban, and based on my own observations, though not scientifically perfect of course, can be 1-2c hotter on a summers day. I reckon it was 33.5c to 34c in Swindon itself that day. If there was a weather station actually in the town, the Heathrow value might not seem so far off.

[keithlucky]

It reached 34C that day at my place of work (Chatteris), the nearest metoffice station at Wittering recorded its highest ever temperature that day of 35.3C, beating the 35.2C reached in August 1998.

I can't see any issues really, there was always going to be variation between stations, for no reason other than there was quite a lot of high level cloud which meant some places missed out of the highest temperatures. Writtle for example only reached a high of 31C, despite this temperature being reached before midday. Cloud being the issue, other nearby stations hit 34C.

Enough maxima of 34/35C were recorded that day over a widespread area to suggest that the high recorded at Heathrow would be valid. As Pete say the station and the runway has been there for many many years, why hasn't Heathrow taken the record before this point?

 

Also it seems the only people banging on about climate seem to be those who deny it anyway, can an extreme event happen due to a series of variables coming together at the right time to produce the perfect set up to break the temperature record. The pulse of heat was the strongest we have seen since the heatwave of August 2003, the temperatures on that day came after 30C was reached the previous day in the south east and many days prior to that had reached the mid to high twenties. I have no problem believing that the record went, but it is only an isolated event based on a perfect synoptic set up, just like halloween last year.

There is compelling evidence that such a sharp temperature peak lasting just 20 minutes was actually caused by 3 long haul flights landing in quick succession, then exacerbated by the SE wind direction and late runway exits.

A BA 747-400 originating from San Francisco, a BA 777 from Tokyo and an Etihan A380

Heathrow wind speed July 1st

superjumbo all landed within minutes of each other  between ~ 14:00 and ~14:30 on July 1.This is when the temperature spike occured.

[Methuselah]

keith. You really are getting desperate.

[Midlands Ice Age]

keith. You really are getting desperate.

 

I thought you had said accurate for one moment!

 

Edited July 20, 2015 by Midlands Ice Age

[BornFromTheVoid]

There is compelling evidence that such a sharp temperature peak lasting just 20 minutes was actually caused by 3 long haul flights landing in quick succession, then exacerbated by the SE wind direction and late runway exits.

A BA 747-400 originating from San Francisco, a BA 777 from Tokyo and an Etihan A380

Heathrow wind speed July 1st

superjumbo all landed within minutes of each other  between ~ 14:00 and ~14:30 on July 1.This is when the temperature spike occured.

 

If it was because of a few jumbo jets landing nearby, wouldn't we see seemingly spurious jumps in temperature happening all the time in Heathrow? And if they could have that large an impact on the hottest day in nearly a decade, wouldn't they cause massive temperature jumps at night and during winter when the difference in temperature between the exhaust and air are at their greatest? Is there any evidence out there for this?

[Relativistic]

keith. You really are getting desperate.

 

I'm fairly neutral on this, I see reasons for the record to be both valid and invalid. He is just making a point. Let him have his say and then let people debate it.

Edited July 20, 2015 by 22nov10blast

[Paul]

Since most flights take off and land at around the same time every day at Heathrow, wouldn't those claiming the temperature change was down to planes landing expect that same spike to occur every day? A cursory glance of the temp data at heathrow for the last couple of weeks shows nothing of the sort. 

 

And regardless, why are some people jumping all over this? It's as if there's some desperate attempt to prove it wasn't that hot as somehow the half a degree difference on what was a hot day may actually prove something worthwhile (I'm not sure what). All seems very strange.

Edited July 20, 2015 by Paul

[Nouska]

for the life of me, I cannot understand what all the fuss is about.

 

Just across the Channel and the North sea, heat records are being broken on a regular basis - what's the big deal if Heathrow manages a monthly heat record?

[Captain Shortwave]

There is compelling evidence that such a sharp temperature peak lasting just 20 minutes was actually caused by 3 long haul flights landing in quick succession, then exacerbated by the SE wind direction and late runway exits.

A BA 747-400 originating from San Francisco, a BA 777 from Tokyo and an Etihan A380

Heathrow wind speed July 1st

superjumbo all landed within minutes of each other  between ~ 14:00 and ~14:30 on July 1.This is when the temperature spike occured.

It could be because the high level cloud over the region cleared, the cloud cleared the region around that time after pushing up from France around midday.

There were peaks and troughs in the temperature across many areas because it wasn't a sunny day and the cloud that did come in from the continent was quite thick and fully obscured the sun (in fact even a few showers were produced). Surely this has much more impact than a few jumbo jets.

Edited July 20, 2015 by Captain shortwave

[knocker]

Since most flights take off and land at around the same time every day at Heathrow, wouldn't those claiming the temperature change was down to planes landing expect that same spike to occur every day? A cursory glance of the temp data at heathrow for the last couple of weeks shows nothing of the sort. 

 

And regardless, why are some people jumping all over this? It's as if there's some desperate attempt to prove it wasn't that hot as somehow the half a degree difference on what was a hot day may actually prove something worthwhile (I'm not sure what). All seems very strange.

 

Well the people who instigated this whole sorry affair are very strange but to follow your point.

 

As Mark McCarthy says, from the Met Office's point of view, it would indeed be concerning if Heathrow temperatures were unduly biased by aircraft exhaust, But he adds:

 

"Because it is a very busy airport, such effects would not be confined to one day. So we should look at the longer data records, rather than one specific time on one specific day."

 

Those longer records show that Heathrow and Kew typically see similar maximum temperatures, though not always at exactly the same time.

 

"On any one day they can differ from each other by wider margin than recorded on 1 July, with Kew being warmer than Heathrow nearly as much as the other way around."

 

In other words, there is no evidence of a temperature bias at Heathrow,

 

Just in passing it brings to mind another story run by the very same mob in 2007 and if I remember correctly it was something to do with an air conditioning unit being too near the screen and was pumping hot air over it. Cast doubts on all the weather stations in Akron, Ohio.

Edited July 20, 2015 by knocker

[Methuselah]

^^ I do hope we are not going to be subject to another round of spurious FOI claims...

[Woollymummy]

Look at the other heat records round the UK for the same day. How many of them were near to an airfield, active or not, and how many were in non-airfield rural or urban locations? How many temperature reports were there that day? Were a disproportionate number of heat spikes from airfields, are airfields always usually the hottest, or only on really hot days?

[hillbilly]

I guess even I think there is little evidence to suggest there is any wrong readings here but it cannot be ruled out entirely without much more scrutiny.A little conspiracy is a good talking debate however and very interesting,i think there is a little debate on the forum on just how Stevenson screens can differ just to throw another spanner in.Just a little off topic but while it is on my mind,why do car thermometers always read artificially high,usually by a couple of degrees?

[Midlands Ice Age]

I think that the unusual thing about this day (and it hasn't been mentioned at all on here as I can see), was the lack of wind. What bit there was came up from the SE.

These are not usual conditions during a heatwave as normally the heat will generate convection currents of its own and hence considerable mixing .  It didn't seem to occur much that day. I suspect that usually the breeze will normally distribute any heat quite quickly; that day around here it was still most of the time. 

 

Could these conditions have contributed to any local heat effect, and Is the runway to the SE of the weather recording station?

 

MIA

[knocker]

Enough said on this moment of climate hysteria from the met office subject put to bed ,http://t.co/3GCHf1koVL

 

In your link to that wonderful scientific blog Homewood  wonders if 0.9C rise in 2 minutes is reasonable.

 

Well Kew Gardens warmed 1.1C in 2 minutes 12:28-12:30 that day.

 

Of course it's not known if this coincided with the passage of a motorised grass cutter nearby.

 

And talking about putting to bed it's about time this nonsense was.

Edited July 21, 2015 by knocker

[keithlucky]

Since most flights take off and land at around the same time every day at Heathrow, wouldn't those claiming the temperature change was down to planes landing expect that same spike to occur every day? A cursory glance of the temp data at heathrow for the last couple of weeks shows nothing of the sort. 

 

And regardless, why are some people jumping all over this? It's as if there's some desperate attempt to prove it wasn't that hot as somehow the half a degree difference on what was a hot day may actually prove something worthwhile (I'm not sure what). All seems very strange.

The question is why locate weather stations near runways ,that the main point i"m making ,were as for example the local weatherman near to me used to feed his data to the met office from  my area,Being that away from built up areas were city heat  can distort your readings.

[Paul]

And yet the station just off the runway at Gatwick (Charlwood) is often one of the coldest spots in the region. 

 

Plus of course, stations need to be representative, a lot of the UK is built up, so why wouldn't you have weather stations in those areas?