The winter of 1939-40 was the coldest for 45 years with a CET of 1.5 and contained one of the coldest months on record.

The winter started off mild, a carry over from the very mild November, CET 8.7 (+2.9) but it became cooler during first fortnight of December. First half December: 4.7

The real cold spell came during the latter half of December 1939 when an anticyclone became established and this brought frosts and fog at night.

January 1940 was a severe wintry month with frequent frosts and heavy snowfalls. The CET for the month was -1.4C, the first sub zero CET month of the 20th Century and the coldest month since February 1895.

After an initial cold start to January, it became milder around the 6th as a southerly flow covered the UK

By the 10th, an anticyclone from Europe extended across the UK and it became colder again with extensive frosts. The first snowfalls came on a northerly as a low pressure pushed into Scandinavia and pressure built over Greenland. The 16th was a particularly cold day in a biting ENE wind and the following few days were some of the coldest of the weather.

Amazing chart for mid January

On the night of the 23rd, a minimum of -23.3C was recorded at Rhaydaer(Powys) a record low for that date. Other lows include -20C at Canterbury, Welshpool, Hereford and Newport in Shropshire.

The Thames was frozen for 8 miles between Teddington and Sunbury and ice covered stretches of the Mersey, Humber and Severn.

The sea froze at Bognor Regis and Folkestone and Southampton harbours were iced over. The Grand Union Canal was completely frozen over between Birmingham and London. Central London was below freezing for a week and there was skating on the Serpentine on 6" ice.

However January 1940 will always be remembered for the snowstorm and icestorm that struck the UK.

SNOWSTORM

On the 26th, two occlusions were moving up from the SW engaged the cold air over the UK. At the same time, the anticyclone over Scandinavia was intensifying blocking the fronts from pushing through the UK, they became stationary over Wales and SW England. This resulted in a great snowstorm across many northern and eastern areas.

Vast areas of northern England reported between 30-60cm of level snow, the higher parts in excess of 60cm+. The snow drifted in the strong SEly wind even in the centre of London. Other reports of snow depths include Eastbourne:- 25cm, Pontefract:- 37cm, Malvern:- 60cm and Exmoor:- drifts of 2.5m. The snowfall lasted to the 29th of January

ICESTORM

On the low ground in the south, the preciptation fell as freezing rain. The raindrops were of the supercooled nature, so when the rain hit the surface it would freeze instantly. This is a rare event in the UK and the 1940 is reckoned to be the severest that has struck the UK in recorded history.

The duration of the storm was remarkable lasting up to 48 hours in places. For instance at Cirencester, 48hrs of freezing rain fell in temperatures of between -2 and -4C. The effect of this prolonged icestorm was severe and damaging. Many telegraph poles and wires were snapped unable to cope with the weight of the ice. Flora and fauna suffered as well, many tree branches were snapped off by the enormous weight of ice, birds were unable to fly because ice accumulated on their wings. Travel was next to impossible as roads and pavements became skating rinks. Any sloped surface was impossible to climb.

The battle between the cold continential air and the milder Atlantic air continued until the end of the month.

The start of February continued the battle and it was the 4th when the Atlantic finally won the skirmish on the 4th. This brought a thaw to the the mass of snow and ice that had accumulated.

The thaw was short lived as the colder air pushed back westwards and it became cold yet again on the 10th.

The winter finally broke on the 20th as mild tropical southwesterlies flloded the UK and the rest of the month was milder

Data for Winter 1939-40

December 1939: 3.2 (-1.5)

January 1940: -1.4 (-5.6)

February 1940: 2.6 (-1.4)

January 1940 is the 11th coldest on record, the nights were especially cold with a CET minimum of -4.5C

The coldest spells of the winter

28th Dec-4th Jan: -1.7

10th-19th Feb 1940: -1.8

10th-24th Jan 1940: -3.5

10th January-19th February: -1.2

28th Dec-19th Feb: -0.8

Second half of January: -2.7

First half of February: 0.8

The mildest CET day: 12.5C 27th February

The coldest CET day: -3.8C 20th January

The coldest CET night: -13.4C 21st January

This was the first winter of the Second World War and the cold hit many parts of Europe. Oporto in Portugal and Corunna in Spain reported heavy snowfalls, the first for many years. In Norway and Sweden, the mercury in thermometers froze, the Danube froze and th morale of Allied men awaiting for the Germans was severely affected by the penetrating cold.

Weather reports in newspapers were severely restricted because of the war with any reports being issued a fortnight after the event.

Here are Guardian reports on the January of 1940

The severity of the cold   

https://i.imgur.com/KFIr5LQ.jpg

Train/transport chaos because of the snow  

https://i.imgur.com/H7MKq2O.jpg  https://i.imgur.com/NX4hjUE.jpg   https://i.imgur.com/66If2zm.jpg   https://i.imgur.com/H3rQ07A.jpg 

Bolier explosions and fog

 https://i.imgur.com/2yMLca2.jpg

Photos  

https://i.imgur.com/YRC4MDZ.jpg  https://i.imgur.com/IDcDGan.jpg  

Buxton isolated

 https://i.imgur.com/8HYWpQP.jpg

Temperatures  

https://i.imgur.com/QmMlfCE.jpg

https://i.imgur.com/fhOeOM4.jpg

https://i.imgur.com/q8fqnOg.jpg

Snowstorm

https://i.imgur.com/FFcmZH2.jpg

https://i.imgur.com/xcVFjyq.jpg

Thanks, Kev. for that excellent report. That ice-storm must have been quite something to have lived through.

Bearing in mind that that January was the first with a sub-zero CET since February 1895, a gap of 45 years,  I sometimes think we complain too much about the recent shortage of cold winters. After all, our last sub-zero month was as recently as December 2010. In my lifetime, I've experienced sub-zero months in February 1956 (I just missed out on February 1947), January and February 1963, January 1979, February 1986 and December 2010, so I feel that I've had my fair share. (And in January 1987 there was probably the coldest day over much of England during the last 150 years or so.)

Amazing thread Kevin - and another for me to put in the classics thread - I'll leave this on here for the next couple of days.

I gather the 23rd January 1940 was the coldest night in the UK until December 12th 1981.

A brilliant read 

Thanks Kev

Yes, my Dad did too and along with 1947, which fortunately/unfortunately  I can remember, led me to having lifetime interest in weather and climate.

He described to me that clouds in the North got darker and darker and nearer until the sky was very dark allover.

It then began to rain very heavily and after about ten minutes the rain began to turn to hail and shortly, it was all hail and the ground was white everywhere. this lasted another ten minutes when the odd snowflake could be seen mixed with the hail. Quickly the snow became dominant and very heavy.

It didn't stop, and accumulated to good depths by the end of the afternoon(?). It snowed all night and all the next day and the day after but gradually over this time getting less intense.

1947 was different. The general and regular theme as described by the weather forecast, was that there would be a warming of 'snow spreading from the south but quickly turning to rain'.

And in Derby the snow did turn to rain - once!

The snow however soon returned.

I think I've told this tale here before, but in our local paper there used to be a weekly feature by this bloke looking at local history.

One story was about a severe snowstorm during wartime that left extremely deep snow and had caused a train to crash somewhere in this vicinity (IIRC around the Newton/Earlestown area, which would make sense given the rail intersections there) I think there were deaths, and I've got it in mind that it was a military train transporting troops. The story was hushed-up at the time due to wartime morale issues.

I contacted the guy sometime later to ask for a copy of the article and although he said he'd dig it out, he never did and I'm pretty sure he's passed away now.

Can't remember the exact year, though. Trying to pin it down, I doubt it was 1939/40, as we were still in the 'phoney war' phase with spirits remaining a bit gung-ho (Dunkirk in summer '40 put a stop to that!), and the articles you've posted seem very detailed; press began to be more censored from later in 1940 (especially about bad news events)

I'm guessing, then, that it would have been either the 1940/41 or 1941/42 winters. Both were cold and snowy, and both hit northern areas more.

It'd be a stretch for you to have details of the event, but if you ever do your excellent articles on these two winters, I'll be reading avidly!