This episode of extreme cold is caused by an anticyclone and the accumulation of snow that prevents the heating of the ground.
The thermometers continue to fall in Spain in general below -10ºC leaving Teruel, Toledo, Madrid, Soria and Burgos with temperatures lower than those recorded in Norway, according to eltiempo.es.
It is an unusual situation in Spain and the best example is the spectacular photograph captured by the two satellites of the Copernicus Sentinel-3 mission of the ESA, in which it is seen how Madrid was one of the autonomous communities most affected by Filomena, although not the only one.
This is the ranking of the coldest Spanish cities:1. In Teruel this morning they were measured -15,4ºC and on Tuesday he beat his historical record with -21ºC.
2 in Toledo Mercury has dropped to -11,5ºC this Wednesday.
3. In the University City of Madrid They have registered -10,9ºC, While in the Retirement were reached -7,2ºC and in the Airport -12ºC.
4. Soria today has registered -9,5ºC.
5. in Ávila have been reached -8,9ºC.These minimum values are much lower to those of European cities such as Berlin (0.1ºC), Warsaw (-1.4ºC) or even Stockholm (-2.7ºC). It has also been recorded colder than Oslo (Norway) where they have had a minimum -8ºC and in Tromso, locality located within the arctic polar circle where the minimum value was -6,6ºC.
Why is it happening?

5 keys to cold snaps
1. What have been the strongest cold snaps?The longest cold wave that Spain has experienced was the one that occurred in December 2001, with an episode of 17 days. Although the most outstanding was that of 1985, the strongest in the last 50 years with a negative anomaly of 5.5ºC and affecting 45 provinces.2. What temperatures occur in a “cold wave”?The temperature to be considered a cold wave depends on each point on the map. The daily minimum temperature must be below the 5% percentile of the coldest dates of the year. That is, be less than 5% of the coldest early mornings recorded in the months of January and February.In addition, for it to be said that there is a cold wave, it has to occur in at least 10% of the territory and for at least 3 days in a row.3. Cold waves and snowfall, do they always go hand in hand?It is not necessary that the episodes of cold are caused by the arrival of air masses of arctic or polar origin in our country. The peninsula is also capable of generating its own extreme temperatures, acting as a freezer capable of retaining very cold air after snowfall.4. There is “The Triangle of Cold”The lowest temperatures in our country have been recorded in mountain areas. especially in the environment of the Iberian system where between Teruel and Guadalajara is the Triangle of Cold where they have reached in other episodes up to -30ºC.5. Cold waves are more deadly than heat wavesAlthough all temperature extremes can be detrimental to health, mortality associated with cold is higher. Cold spells are linked to respiratory problems.Although in Spain it is more common to hear recommendations during heat waves, a study indicates that on average mortality rises by 3.5 people per province in Spain when there is a cold wave.