[Mesogeiakos]

Hi guys

I have been trying to collect mainly the temperature extremes for ''London'' (and by extremes I mean the all time extremes) . By saying London I am willing to accept any official station within either ''Greater London'' , ''London commuter belt'' , ''Metropolitan London''.Those definitions vary significantly in terms of what is considered London...I would not mind accepting the ''London commuter belt'' as ''London'' since it is a much wider area but I reckon it must be a headache collecting all this data.


Would you guys be willing to give your input for any extremes for the ''London'' area? Be it temperature,rain,snow depth,etc...I am aware it requires quite a lot of research but we could use this thread as reference.

My main difficulty is spotting London's absolute minimum from a reliable reference and an official station.There have been reports of -21C or lower for example in Greenwich but that is way back in the 1700's....so I am a bit at a loss with this issue.Any helping hand?

This post has been edited by Mesogeiakos: 21 March 2012 - 14:55

[Ian Williams]

Hers a few to start with not necessaril in any order lol

February max Greenwich 19.7C 13th Feb 1998

April Camden Square 29.4C 16th April 1949

May Camden Square 32.8C 22nd May 1922 & 29th May 1944 & Regents Park 29th May 1944

June Camden Square 35.6C 29th June 1957

July Camden Square 35.6C 13th July 1923

August Kew Gardens 38.1C 10th August 2003

September Barnet 35.0C 2nd September 1906

October St James Park 29.1C 1st October 2011

November Tottenham 21.1C 5th November 1938

This post has been edited by Ian Williams: 21 March 2012 - 15:23

[Dave K]

A bit random but...

UK Highest 155-minute rainfall total

169 mm

14 August 1975

Hampstead (Greater London)

[Mesogeiakos]

Nice one!Thank you both

Any idea of what is the most reliable reference for London's absolute minimum?

[Ian Williams]

Also highest amount in 100 minutes


116 mm West Wickham Greater London 22 July 1934

[Ian Williams]

Mesogeiakos, on 21 March 2012 - 15:45, said:

Nice one!Thank you both

Any idea of what is the most reliable reference for London's absolute minimum?

Not sure about reliability but found this

UNITED KINGDOM

 Greater London    -18.8* 38.1    * - 21.1C also recorded in December 1796 and January 1795

 London Greenwich  -16.1  37.5

http://www.mherrera.org/temp.htm

This post has been edited by Ian Williams: 21 March 2012 - 15:57

[Dave K]

Mesogeiakos, on 21 March 2012 - 15:45, said:

Nice one!Thank you both

Any idea of what is the most reliable reference for London's absolute minimum?

Good question - as you suggest there are so many options in what is now Greater London, but the spread of the city was much less in the 18th century. For central(ish) London: Kew Gardens, St James Park, Greenwich and Hampstead look reliable; really not too sure about Camden Square which probably wouldn't pass muster now and the old London Met in Clerkenwell was a non-standard rooftop site. Don't know anything about the Regents Park, Tottenham or Barnet sites (or any others)

I've seen -18.8 °C quoted as the record min for "London" but no idea which site or when that was.

[Dave K]

Right found that the -21 °C (which would have been a Fahrenheit reading then) was at Marylebone on 25th December 1795 also -19 at Mayfair, so that counts as central London. Booty weather gives the year as 1796 though for that, and I've seen the date as 25th January 1796 too!

This post has been edited by Big Dave's Gusset: 21 March 2012 - 16:25

[Bluebreezer54]

Regarding London weather I find this website very interesting, with information going back as far as 1900, and some pretty good summaries as well.

http://www.london-weather.eu/

[HSEA2]

I pretty sure i saw (on one of those PDFs made public from the Royal met soc) temperature's of -25c or -26c recorded at Walton on Thames and Beckenham.

HOWEVER, given Kew goes back to around 1870 and has never been lower than -12.8c, and was probably more or less rural (and it seems more of a frost trap than heathrow on many nights, even now) before the 20th century i am VERY suspicious of anything below -15c be it in the 20th century or 18th.

In fact given around -13 is also the record min for Heathrow (since 1946) and Hampsted (since 1910), i think its pretty representative of the entire London region. St James park record low is -10c, LWC, as far as im aware, just -8c, illustrating the central warmth.

[Dave K]

HSEA2, on 21 March 2012 - 17:22, said:

I pretty sure i saw (on one of those PDFs made public from the Royal met soc) temperature's of -25c or -26c recorded at Walton on Thames and Beckenham.

HOWEVER, given Kew goes back to around 1870 and has never been lower than -12.8c, and was probably more or less rural (and it seems more of a frost trap than heathrow on many nights, even now) before the 20th century i am VERY suspicious of anything below -15c be it in the 20th century or 18th.

In fact given around -13 is also the record min for Heathrow (since 1946) and Hampsted (since 1910), i think its pretty representative of the entire London region. St James park record low is -10c, LWC, as far as im aware, just -8c, illustrating the central warmth.

Of course, while 1795 or 1796 may well have been extremely cold we know nothing about the exposure and it was long before Stevenson Screens were around so even if the sites were still more suburban in nature in Georgian times the accuracy certainly has to be questioned.

In the UKMO records for 1921 - 1950 period Greenwich recorded 9 °F or -12.8 °C, and that period had some very cold winters.

[Dave K]

A note from Trevor Harley's site

January 1962

Quote

London recorded its lowest ever minimum (under standard conditions), with -16.1C at Northolt on the 1st

http://www.personal.dundee.ac.uk/~taharley/british_weather_in_january.htm

[StephenS]

A localised temperature in rural or semi-rural parts of the London area of -20 or lower seems plausible to me.

Rickmansworth, Benson and Chesham aren't a million miles away, and have clocked up some impressively low -and verifiable - readings over the years. I'd be very surprised though if such minima were reached away from frost hollows or in urban areas.

[Mesogeiakos]

Big Dave, on 21 March 2012 - 17:44, said:

A note from Trevor Harley's site

January 1962



http://www.personal.dundee.ac.uk/~taharley/british_weather_in_january.htm

Ok thats interesting I didnt know about this one.Given that particular cold spell I am pretty sure this one at least is reliable.But I agree that surely ''London'' must have seen lower localized temps in semi-rural or rural areas.-20C would seem plausible..

This post has been edited by Mesogeiakos: 21 March 2012 - 18:06

[Dave W]

Even this year saw -18.1C at Chesham ..

[Dave K]

StephenS, on 21 March 2012 - 17:53, said:

A localised temperature in rural or semi-rural parts of the London area of -20 or lower seems plausible to me.

Rickmansworth, Benson and Chesham aren't a million miles away, and have clocked up some impressively low -and verifiable - readings over the years. I'd be very surprised though if such minima were reached away from frost hollows or in urban areas.

Mesogeiakos, on 21 March 2012 - 18:04, said:

Ok thats interesting I didnt know about this one.Given that particular cold spell I am pretty sure this one at least is reliable.But I agree that surely ''London'' must have seen lower localized temps in semi-rural or rural areas.-20C would seem plausible..

Again I think this depends on what we want to consider as "London" (which changes over the last couple hundred years too, many suburbs were still distinct villages up to the mid 19th century). It's probably best to separate for clarity into the Inner London Boroughs and the Outer London boroughs - and anything outside that just isn't London!

[HSEA2]

Big Dave, on 21 March 2012 - 17:44, said:

A note from Trevor Harley's site

January 1962



http://www.personal.dundee.ac.uk/~taharley/british_weather_in_january.htm

Sounds about right, IIRC Northolt got down to -14c or so in December 2010.

[StephenS]

I totally agree. I think it's unlikely that we'll see such low temperatures in London (however liberally one defines the boundaries). But I'm reasonably comfortable with the proposition that they may have been reached in the past, in what were at the time quite rural locations. We'll never know of course...

This is quite interesting, though it lacks citations:

http://www.netweathe...r-history;sess=

[Mesogeiakos]

Fair enough Dave.What is a good definition in your books for say Inner London and then Outer London boroughs bsc we still get conflicts over these definitions as well...


Which would you class as Outer London Boroughs and are we going to stick with the strict administrative limits of each Borough?

HSEA2, on 21 March 2012 - 18:18, said:

Sounds about right, IIRC Northolt got down to -14c or so in December 2010.

I think it was closer to -15C actually...if memory serves me well it must have been -14.8C

[Mesogeiakos]

lol got it!Lets go by the London Government Act 1963

http://en.wikipedia....rnment_Act_1963

http://en.wikipedia....ki/Outer_London

This post has been edited by Mesogeiakos: 21 March 2012 - 18:33