The weather in the 1st quarter of 2020 (January, February, March), heating degree days from April 2019 to March 2020.
Locally, the very warm January was already in the record range. Nationwide, February was the second warmest since measurements began in 1864. The whole quarter was rather low in precipitation.
Very warm and dry January
At altitudes over 1000 meters, Switzerland registered the third warmest January since records began in 1864. On the northern side of the Alps it was the sunniest January in the region since records began. January was extremely low in precipitation throughout Switzerland. From January 1st to 25th, several high pressure areas passed over Switzerland from the west and south-west and brought a lot of sunshine in the Alps and on the south side of the Alps. In mountain areas and on the Jura heights, very mild conditions prevailed almost throughout the day, while fog or high fog often lay over the central and eastern plateau. The persistent high-pressure weather was only interrupted for a few days by weak fault zones running through it.
Stormy westerly winds: From January 26, low-pressure areas determined the weather in Switzerland. In the night from January 27th to 28th, a stormy westerly current set in. In the morning and evening of January 28, there were widespread heavy showers, some as sleet and snow, accompanied by thunder and lightning and gale force winds, and the snowline fell regionally to 400 meters. The wind peaks reached 55 to 90 km/h in the lowlands on the north side of the Alps, regionally up to 120 km/h and 110 to 150 km/h in mountainous areas. On January 29, the storm continued with slightly lower wind peaks. The southern edge of the Alps was quite sunny with maximum temperatures of around 14 degrees. The last nocturnal disturbance occurred from January 30th to 31st, while during the day there were a few hours of sunshine throughout Switzerland.
Monthly balance for January 2020: According to MeteoSwiss, the average January temperature was 2.4 degrees above the 1981-2010 norm.
In mountainous areas, January temperatures of 3 to 3.6 degrees above the norm were recorded. On the southern side of the Alps, January values of 1 to 2 degrees above the long-term average were recorded. The amount of precipitation in January on the southern side of the Alps and in the Engadine was only 10 to 30%, regionally even only 5 to 10% of the norm.
In the other areas of Switzerland, mostly only 30 to 60% fell, locally also by 70% of the long-term mean. The duration of sunshine in January north of the Alps and on the northern slopes of the Alps was 150 to 220% of the norm. In the other areas of Switzerland, it ranged widely between 120 and 150% of the average. January delivered new sunshine records at the measuring locations in Bern, Geneva, Zurich and Basel, which have records going back more than 100 years.
Second warmest February since measurements began
February was very warm and stormy and was the second warmest February nationwide since measurements began in 1864. In addition to the monthly record, there were numerous records for daily highs, some with 18 to over 20 degrees.
February was often dominated by southwesterly currents, which brought mild or subtropical and humid Atlantic air masses to Central Europe. With the imported warmth, the mean daily temperature in Switzerland from 1 to 24 February was almost consistently well above the norm. The mean daily temperature rose to new February records at almost 40 measuring locations. Most of them were registered on February 3, 23 and 24.
Stormy February: February 2020 was unusually stormy.
25 days of storms were counted on the Säntis and the Chasseral. It was the stormiest February month since measurements began in 1981 at both measurement locations. In the lowlands on the north side of the Alps, the stormiest February since measurements began in 1981 was recorded locally. In the first half of February three winter storms swept across Switzerland, Petra on the 4th, Sabine on the 10th and Tomris on the 13th/14th. Storm Sabine on February 10 developed the strongest. In the Central Plateau, wind peaks reached 90 to 120 km/h. On the heights of the Jura, the maximum values rose to 140 to 160 km/h and to 160 to 200 km/h at the summits.
Danger of forest fires in the south: After January with very little precipitation, the southern side of the Alps also received extremely below-average precipitation in February. In general, less than 10% fell, in some areas even less than 5% of the norm. The persistent lack of precipitation led to a great risk of forest fires on the southern side of the Alps. A similar lack of precipitation during the months of January and February can be expected in southern Ticino about every 15 to 20 years.
Monthly balance February 2020: According to MeteoSwiss, February was 1.6 degrees on average 3.9 degrees above the norm across the country.
Switzerland thus recorded the second warmest February since measurements began in 1864. The southern side of the Alps recorded a massive February record. In the lowlands of Ticino, the February temperature was 8.1 degrees or almost 4 degrees above the 1981-2010 norm. In February, the amount of precipitation on the southern side of the Alps mostly remained below 10%, locally even below 5% of the norm. In the Engadin, the amounts were between 60 and 100%. In the rest of Switzerland, the regular south-west currents with their mild, humid Atlantic air masses caused plenty of precipitation. The totals reached 150 to 200%, regionally also 200 to 250% of the norm. The duration of sunshine increased in February north and south of the Alps to 120 to 140% of the norm. Western Switzerland registered regionally up to 150%, central Switzerland locally up to 160% of the long-term average. In the Alps, the duration of sunshine varied widely between 80 and 100% of the norm.
Changeable March
March was predominantly characterized by high pressure.
The national mean temperature in March was 0.8 degrees above the 1981-2010 norm. Rainfall levels remained well below average. In the first ten days of March, low pressure and high pressure alternated every two days. In many areas of Switzerland, precipitation fell almost every day. From March 11th to 20th, high pressure areas stretching from the Atlantic to Europe determined the weather and brought mild air masses to Switzerland with west and south-west currents.
During the first massive surge of heat on March 11th and 12th, the daily average temperature rose 5 to 7 degrees, locally also 8 to 10 degrees above the norm. During the second heat wave from March 16th to 20th, combined with lots of sunshine, the mean daily temperature rose widely by 4 to 8 degrees above normal.
Strongest cooling in the winter half-year: On March 21, a strong high-pressure area built up over Scandinavia, which slowly moved towards the south-east in the following days.
Cold mainland air flowed to Switzerland along its southern flank. The mean daily temperature fell on both sides of the Alps by 3 to 5 degrees, locally also by 5 to 7 degrees below normal. In Switzerland, the mean daily temperature never fell so far below the norm during the entire winter half-year 2019/2020. The cooling on the southern side of the Alps was particularly striking. There were several frosty nights in the lowlands on both sides of the Alps. The minimum values at a measuring height of 2 meters were 3 to 6 degrees below freezing in some areas. In many places directly above the ground, the values dropped 7 to 10 degrees below zero.
Monthly balance for March 2020: According to MeteoSwiss, the average temperature in March was 0.8 degrees above the 1981-2010 norm. North of the Alps it was widely 0.5 to 0.9 degrees, in western Switzerland locally 1.0 to 1.2 degrees above the norm. In the Alps, the values ranged from 0.8 to 1.3 degrees, on the southern side of the Alps, however, only 0.1 to 0.6 degrees above the long-term average. Rainfall levels in March generally reached 60 to 90% of the norm. In the Engadin and in the Davos region, there were quantities around 100%. In the lower Valais and in the Lake Geneva region, the values rose to 100 to 120% of the long-term average. In March, the amount of sunshine increased across the board north of the Alps to 130 to 150% of the norm. In the Alps, the duration of sunshine varied widely between 100 and 130% of the average. The southern side of the Alps usually registered 90 to 100% of the long-term average.
