November 1919 (99 years ago) recorded one of the most extraordinary cold spells in the history of the UK and Ireland. The fact the cold spell occurred in mid-November (not even the end of the month) says it all really. The November 1919 cold spell is my second favourite weather event to research or discuss about after November/December 2010 as I find it so fascinating how it could be as cold as it was then (Autumn 1919 in general was extremely intriguing, not November alone). Just goes to show how cold it can get in mid-November if the setup is there.
The pattern of November 1919 was similar to that of November 2010. There was blocking over Greenland with anomalous below average heights to the southeast of the UK driving winds in from the northeast with air coming from Scandinavia. The 500mb height anomaly reanalysis of November 1919 below shows this.
The first ten days of November were rather cold already with some overnight frost and light easterly winds at first, gradually becoming windier. The easterlies led to a lack of sunshine for many especially to the south of the UK and east of Ireland. These days were just damp, quiet and chilly.
The cold spell really took hold on the 11th (my birthday
) with northeasterlies dominating. There was plenty of snow showers. There was reports of thundersnow including for Blackpool in the northeast of England. A snowstorm occurred overnight into the 12th in Scotland as a secondary low passed within the severely cold air. Villages were cut off by the snow. There was a foot of snow (30cm) at Dartmoor, 17 inches (44cm) at Balmoral and 8 inches (20cm) at Edinburgh. At Balmoral, this snow continuously laid on the ground from the 8th to 30th November. The snow showers continued for a few days up to the 16th.
Light northeasterly winds and pressure rising led to bitterly cold temperatures being recorded. The snow cover acted as an excellent insulator in further dropping the temperatures to abnormally cold levels for mid-November (probably unprecedented) especially over Scotland. Braemar got down to a whopping -23.3c on November 14th! That is an exceptionally low temperature in the middle of Winter, never mind mid-November. This is the November record low temperature for the UK to the present day when writing this. November 14th 1919 is the earliest a minimum temperature of -20c (AND -15c!) has been recorded in the UK. This is such a phenomenal figure in many ways as you can see. On the same day, Perth got down to -21.7c. Balmoral recorded afternoon maximum temperatures of -10c on the 14th and -12c on the 15th. The temperature fell again to -22.8c on November 15th at Balmoral, the second earliest -15c/-20c temperature in the UK and the second lowest November temperature on record. The maximum at Carlisle, Cumbria in England on November 14th was only -2.7c whilst England's lowest minimum was -12.8c at Scaleby on the 16th. Lisburn in Northern Ireland recorded a minimum of -12.2c on November 15th, Northern Ireland's November record low to this day. 2010 got close at -11.9c on the 28th but not quite beating the 1919 record.
After the 17th, the weather turned more changeable with day to day variation of mild and cold. There were further instances of snow, sleet and hail from the 20th-23rd. Was the extraordinary cold going to become a distant memory or would Winter 1919-20 continue the cold? Winter 1919-20 was unsettled and mild so the November cold was to become the coldest weather of the whole season.
Lowest minimum temperatures of November 1919 for various Irish stations (via the UK Met Office monthly weather report).
*The -11.1c temperature at Markree Castle on November 14th 1919 was the record low November minimum temperature for the Republic of Ireland until 2010 when it was beaten at -11.5c by Clonroche, Co. Wexford.
At a CET of 3.3c, November 1919 was the equal 7th coldest on record back to 1659. Just 4 years before, November 1915 was the second coldest on record with a CET of 2.8c (the coldest being 1782 at 2.3c). The coldest CET we've seen since 1970 was November 1985 at 4.1c in comparison. November 1915 was persistently cold and frosty whilst November 1919 had an extreme cold spell but was moderated later.
Data comes from the UK Met Office.