Although the temperatures at the Berlin-Tegel station rose by 1.6 °C in the last 50 years, there is no marked difference in the increase of summerly threshold days in comparison with the other five stations. In the trend, the number of summer days in 2013 was 16 days above the initial values in 1963; the number of hot days increased by four days.
With respect to the number of tropical nights, the Tegel station has a middle position together with the one in Tempelhof. The highest nocturnal temperature values as well as the highest number of tropical nights (in total and related to individual weather events) are recorded at the inner-city Alexanderplatz (cf. Fig. 2-3). The lowest number is recorded at the peripheral sites Dahlem and Grunewald. This close relationship with the urban location comes about mostly because the nocturnal minimum temperatures more closely reflect the degree of development of the surroundings than the daytime maximum values.
In the period under consideration, a stretch of 8 days with consecutive tropical nights was observed in the time from July 23 to July 30, 1994. This value was not surpassed even in the ‘hundred-year summer’ of 2003 with 67 summer days, 31 of them consecutive from July 14 to August 13, at the Tegel station (cf. Fig. 5.7).