Scottish Highlands experience 16.8C December temperature record

30 December 2019, 08:36

The highest ever temperature recorded for the UK this late in the year was early on Sunday morning in the Scottish Highlands.

A Met Office observation post in Cassley, in Sutherland, north Scotland, recorded a temperature of 16.8C at 3am on Sunday morning - this was well above the average nighttime temperature for that area in late December of zero degrees.

However given how early in the morning the high temperature was recorded, most people would have slept through it.

Met Office forecaster Alex Burkill said it was the highest UK temperature recorded this late in the year.

He said: "It is pretty exceptional. We have never recorded a temperature that high this late in the month. What makes it more unusual was the temperature came at 3 am."

According to meteorologists, Sunday's record is down to a process called the Foehn effect - which the Met Office says is "a change from wet and cold conditions one side of a mountain, to warmer and drier conditions on the other (leeward) side".

In the UK, the most notable Foehn events tend to occur across the Scottish Highlands where the moist prevailing westerly winds encounter high ground along Scotland's west coast.

This results in a marked contrast in weather conditions across the country with the west being subjected to wet weather, while the lower-lying east enjoys the warmth and sunshine of the Foehn effect.

Overnight, mild air from Africa pushed across the UK. As the air travelled from the south-west over the UK, it rose up and lost its moisture. This meant that the other side of the hills ended up with drier air.

There is no indication that the warm nights will last, the Met Office said.

The UK is experiencing warmer than average temperatures at the moment but is yet to reach the record high for December, which stands at 18.3C and was recorded in December 1948 in Achnashellach.

2019 has seen record-breaking temperatures, including the warmest winter day on record, which was 21.2 °C recorded at Kew Garden on 26 February.

The hottest day on record: 38.7 °C recorded at Cambridge University Botanic Gardens on 25 July.