With an average of just 2 mm (0.079 inches) of precipitation, the Swiss lowlands (from Lake Geneva to Lake Constance) experienced their driest December since records began in 1864. In the region's west, there was no precipitation at all.
"In the long-term average (1981 - 2010), the average December precipitation is around 90 mm (3.54 inches)," MeteoSwiss said and added that the current situation is extremely rare.
"During the 153-year period of measurement, only two Decembers were as dry as the one in 2016," the agency said. "The December of 1963 saw 4.8 mm (0.18 inches), while the one in 1864 saw 6 mm (0.23 inches)."
Swiss lowlands precipitation in December since 1864. The dashed line shows the 1981 - 2010 average (87 mm / 3.42 inches). Credit: MeteoSwiss
Less precipitation there was only registered in September 1865 with 1.7 mm (0.06 inches) and in April 1893 with 1.1 mm (0.04 inches).
The southern side of the Alps has also registered an extremely dry December. In Lugano, there was only 1.4 mm (0.055 inches) of precipitation and in Locarno-Monti only 3.4 mm (0.13 inches). Similarly dry Decembers occur there every 15 to 20 years.
Precipitation in Switzerland from December 1 - 28, 2016. Credit: MeteoSwiss
December 2016 was also marked by strong contrasts. While the Jungfraujoch registered the third warmest December since measurements began, with 3.6 °C (6.48 °F) above the 1981 - 2010 standard, the December temperature in Basel remained 1.2 °C (2.16 °F) below the standard.
Persistent high pressure
From December 1 to 8, high-pressure conditions were the decisive weather element. There was plenty of sunshine on the southern side of the Alps and in the Alps.
At higher altitudes, the daily average temperature was clearly above the 1981 - 2010 standard. Particularly mild conditions prevailed in the mountains from the 7th to the 10th, with values 6 to 10 °C (10.8 to 18 °F) above normal.
On the Jungfraujoch, at an elevation of 3 580 m (11 745 feet), the daily average temperature on December 10 rose 11.7 °C (21.06 °F) above normal. It reached an extremely mild value of -0.1 °C (31.8 °F). It was the second highest winter day temperature since the measurements there began in 1933.
In the lowlands, daily average temperatures remained 2 to 4 °C (3.6 to 7.2 °F) below normal.
The agency noted that the final report on December 2016 will be available on January 13, 2017 in the Climate Reports section.
Featured image credit: Daniel Gerstgrasser