Monthly review January 2023
With a mean temperature of 3.9 °C, the high winter month of January was 4.6 degrees above the
climate reference value 1961-1990 and thus presented itself more as an average March month. This puts January in fifth place among the warmest January months since 1961. The record holder is still January 2007 with 5.0°C.
In addition, a new record of daily temperature maxima for the month was reached on 2 January 2023 at Garsebach near Meißen with a maximum temperature of 17.8°C. At this station there were 11 frost days (minimum air temperature below 0 °C) and not a single ice day (daily maximum air temperature below 0 °C). Fig.1 illustrates the course of the two temperature variables.
The sun shone for a total of only 35 hours in Dresden-Klotzsche. This corresponds to a minus of 18 hours. In the ranking of all January months since 1961, only 9 months had less sunshine. On 13 days there was no sunshine at all. In the second half of the month there was not a single ray of sunshine on 10 cloudy days in a row (from 20.1. to 29.01.).
The sum of all individual precipitation measurements reached 31.5 mm in Coswig in January. The monthly total thus corresponded to only 82 % of the normal value for January. After the very dry December 2022, we thus again registered a winter month that was too dry. The precipitation balance for the year 2023 thus starts with a minus of 7 mm.
A very unusual air pressure distribution occurred in the last decade of January. A high-pressure
wedge extending from the eastern Atlantic to Russia led to an extraordinarily large-scale high-fog situation (here 10 cloudy days in a row) over large parts of Europe. Fig.2 shows this elongated grey area of high fog very clearly. Only the highest elevations of the low mountain ranges protruded from the sea of fog. It was noticeable that there were sometimes no fluctuations in air temperature between day and night. From 22.1. to 25.1. this is particularly clearly reflected in Figure 1 by the proximity of the two curves.
In January 2023, partly heavy precipitation was recorded in the west and north of Germany. In our region, lee effects (Föhn) led to a weakening of the approaching rain areas and ultimately even to a precipitation deficit in January.
Fig.1: Temperature course in January 2023 at the DWD station Garsebach near Meissen. The maximum shown on 2 January 2023 (17.8 °C) represents a new record for January temperatures since 1961.
Fig.2: Satellite image of cloud distribution over Europe on 25 January 2023. The unusually extensive sea of high fog from the eastern Atlantic to Russia stands out clearly in the image. Source: FU Berlin.
Autor: Wilfried Küchler