Climate in Austria

The climate in Austria can be classified according to the descriptive classification of the humid- warm temperate zone . In the west and north of Austria there is an oceanic climate , often characterized by humid westerly winds . In the east, on the other hand, a more Pannonian- continental climate with little precipitation with hot summers and cold winters predominates . The influence of low- pressure areas with heavy rainfall from the Mediterranean area is particularly noticeable in the Southern Alps .

In fact, the regional climate of Austria is strongly influenced by the alpine topography . There are often considerable climatic differences within short distances and slight differences in altitude. With increasing altitude, boreal and tundra climates are initially encountered, and even polar climates in the summit areas. Not only the main Alpine ridge acts as a climatic divide . Sun- rich Föhntal valleys (e.g. Inntal ) contrast with fog-prone basin landscapes (e.g. Klagenfurt Basin ), mountain rims with high rainfall (e.g. Bregenzerwald ) contrast with inner-alpine dry valleys (e.g. Ötztal Alps ).

Climatic condition

The description of the current state of the climate in Austria applies to the 30-year reference period from 1971 to 2000.

Air temperature

Average monthly air temperature in January in Austria

Average monthly air temperature in July in Austria

The total range of the annual mean air temperature in Austria extends from over 11  ° C in the inner districts of Vienna to below −9 ° C on the summit of the Grossglockner . In the densely populated lowlands it is mostly between 8 and 10 ° C. The area mean is 6.0 ° C - this is about 9 degrees lower than the global area mean. The annual mean zero degree Celsius isotherm is at an altitude of about 2200 m. In closed basins, valleys and hollows below 800 to 1200 m above sea level, temperature increases with altitude often occur in the winter months ( temperature inversion ).

While in most of Austria January and July are on average the coldest and warmest months of the year, in the high mountains it is February and August. The long-term January mean air temperature in the flat landscapes of the east lies between 0 ° and −2 ° C, drops to −2 ° to −5 ° C at around 500 m above sea level and moves between −4 ° and −6 at around 1000 m ° C. The lowest value in the area of ​​the highest peaks is around −15 ° C. In July the long-term mean values ​​in the east fluctuate between 18 and 20 ° C, at 500 m above sea level between 16 and 18 ° C and at 1000 m between 13 and 15 ° C. On the Grossglockner, the average zero degree limit is not exceeded even in midsummer.

Due to the inversion, the cold poles of Austria can often be found in the Lungau and in the upper Murtal , in the middle Ennstal , in the basin landscapes of Lower Carinthia or in the upper Waldviertel . The lowest temperatures there reach values ​​like those on the three-thousand-meter peaks : the absolute negative record in the lowlands of -36.6 ° C in Zwettl Abbey (505 m above sea level) from 1929 reaches the one measured in 1905 at the Sonnblick Observatory (3106 m above sea level) -37.4 ° C. Experimental single measurements in spatially unrepresentative unfavorable locations confirmed even lower values: −52.6 ° C in the winter of 1932 in the Grünloch sinkhole (1270 m above sea level) near Lunz are also alpine and Central European cold records.

The highest temperatures on the hottest days of the year are mostly measured in the far east of Austria, at the transition to the Pannonian Plain , or in low-lying Alpine valleys under the influence of the foehn. The Austrian record temperature was recorded in Bad Deutsch-Altenburg with 40.5 ° C in 2013.

Precipitation

Mean annual total precipitation in Austria

The distribution of total precipitation in Austria is characterized by two basic factors: On the one hand, precipitation increases with rising sea level, on the other hand, the location in the damming ( windward ) or in the rain shadow ( lee ) of the prevailing flow direction plays a role. In this regard, the main Alpine ridge represents a climatic divide.

With the frequent west to north-west locations, the Bregenzerwald and the entire Northern Limestone Alps (from the Lechtal Alps to the Karwendel , Hochkönig , Dachstein and the Dead Mountains to Hochschwab and Ötscher ) are in the windward direction . The same applies to the southern border of Austria (in the Carnic Alps and the Karawanken ), which receive intense accumulation of precipitation when flowing in from the Mediterranean area . Together with the central alpine Hohe Tauern , the measured annual precipitation totals in the regions mentioned reach a long-term average of around 2000 mm , in some cases around 3000 mm. Especially in the central Bregenzerwald, even the valley areas register an average of 2300 mm of annual precipitation.

In contrast, the eastern Waldviertel (especially Unteres Kamptal ), the Weinviertel (especially Laaer Ebene), the Vienna Basin and Northern Burgenland receive less than 600 mm of precipitation in the course of a year. As the place with the lowest rainfall in Austria, Retz can be named with just under 450 mm.

The average area in Austria is around 1100 mm for the year. The summer half-year (April to September) accounts for slightly more than 60% of the annual total, and the winter half-year (October to March) accordingly a little less than 40%. This distribution of precipitation proves to be very favorable in terms of vegetation development. While in the vast majority of the country the wettest month due to convection (showers and thunderstorms) falls in June or July, the Carinthian Lesach Valley is the only exception: With a primary precipitation maximum in October, it is part of the Mediterranean precipitation climate.

snow

The abundance of snow depends mainly on the altitude and the location of the area in relation to the main flow directions and varies accordingly. The greatest amount of snow falls below 1200 m above sea level in the coldest month, January. In the higher altitudes, the time with the most abundant snowfalls shifts to March and April because of the milder air masses that are rich in water vapor; in the highest altitudes it is from May to early June.

While the average annual snowfall in Austria is around 3.3 m of fresh snow, it is only 0.25 m at Krems and 22 m at the Sonnblick. The limit with year-round snow cover is in the Northern Limestone Alps at 2700 m, in the Hohe Tauern at 2900 m and in the Ötztal Alps at just over 3000 m above sea level.

sunshine

Winter inversion weather conditions are often characterized by thick blankets of high fog . The places with the longest sunshine duration are usually above the typical upper fog limit , such as the terraces in the Tyrolean low mountain range , in the Niedere Tauern and in the Eisenerzer Alps as well as along the southern roofing of the Carinthian low mountain range, with up to 2100 hours of sunshine a year and one relative high proportion in winter. The area around Lake Neusiedl, Marchfeld, parts of the Weinviertel and the central Waldviertel, with an average of around 1850 to 2100 hours of sunshine, are almost as rich in sunshine, but with relatively favorable tanning in the summer half-year. So while in winter in many low-lying areas of Austria fog significantly restricts the irradiation conditions, this is the case in summer due to increased cloud cover in the mountains. Overall, the annual sunshine duration with less than 1500 hours is lowest in large parts of the northern congestion areas. In heavily shaded north walls, much smaller annual sums are possible. The Austrian mean of the annual absolute sunshine duration is 1,600 hours.

wind

In addition to the large-scale wind conditions caused by weather situations related and are modified by the topography, local and regional wind systems have a nearly as important. Precise knowledge of the mountain and valley wind systems , which develop on a small scale in large-scale weather conditions with weak currents , depending on the type of landscape, is particularly important with regard to the ventilation of a valley ( air quality ). The foehn is known among the local winds. The southern foehn is particularly effective bioclimatically , less the northern foehn.

Climate change

Development of the annual mean air temperature (top), the annual total of precipitation (middle) and the annual total of sunshine duration (bottom) since the beginning of instrumental measurements in Austria (without summit stations) as deviations from the mean value of the 20th century (individual years and 20-year low-pass filter)

Since the beginning of the 20th century, the global mean temperature has increased by almost 1 ° C. In Austria, as in the entire Alpine region, the temperature increase was as high as 2 ° C. However, the heating did not take place continuously, but was superimposed by phases of rapid heating and intermittent cooling.

For most of Austria no trend towards more precipitation can be determined, neither in winter nor in summer. In the west (Vorarlberg, North Tyrol), precipitation increased slowly from 1860 to 1980, while in the south-east (Carinthia, Southeast Styria, South Burgenland) it decreased slightly from around 1800 - both primarily in the winter half-year. No long-term change can be seen in the more continental northeast of the country.

Since around 1980 there has been a rapid increase in the duration of sunshine in Austria, similar to the temperature. This is partly due to the northward shift of the summer subtropical high pressure areas , which more often bring good weather to the Alpine region.

While heat waves intensified especially after 1980, episodes of cold weakened at the same time. There was no general increase in temperature fluctuations. The flow rates of the Danube leading to floods have not shown any increase since around 1830. The storminess has not increased since around 1900.

The actual consequences of climate change in Austria are already clearly noticeable: the glacier area in Austria has more than halved from around 1011 km² (1850) to 470 km² (1998) since the middle of the 19th century. Furthermore, a decline in the spread of permafrost can be observed in the high mountains , which destabilizes the rubble and rocky slopes. A problem for winter tourism is the decline in the proportion of snow in total winter precipitation, which is already clearly measurable in locations below 1000 m above sea level. While z. For example, in Kitzbühel (790 m) in the 1960s the proportion of snowfall in winter precipitation almost twice outweighed that of rain, but since around 1990 there has been roughly the same amount of rain as snow. The greatest decrease in both snow thickness and days with snow cover since 1900 was observed south of the main Alpine ridge.

Climate measurement

The location of the Kremsmünster climate observation, the "mathematical tower", in 1891

The Hann-Haus on Hohe Warte in Vienna, the seat of ZAMG since 1872

As early as 1660, climatic measurements that have not been preserved for a few years are said to have been carried out in Innsbruck as part of the Italian experimental measuring network Accademia del Cimento . The records of the Jesuit College in Vienna from 1734 to 1773 are also still missing .

The measurements of the Benedictine monk Placidus Fixlmillner in the Upper Austrian monastery Kremsmünster , whose weather chronicle forms the beginning of the longest surviving Austrian temperature series from 1767, were more sustainable . The Viennese temperature series, which has been preserved since 1775, was established at the university. Franz Zallinger, university professor for physics and mathematics in Innsbruck, founded the series there in 1777. These three stations were integrated into the international measurement network of the Societas Meteorologica Palatina , also known as the Mannheim Meteorological Society . The society ensured international standardization of meteorological measurement practice and published the collected results in the so-called ephemeris, which appeared from 1783 to 1795.

In 1848 Karl Kreil , then director of the observatory in Prague , began to set up the Austrian observation network. In 1851 he was able to officially establish the kk Central-Anstalt für Meteorologie und Erdmagnetismus ( Central Institute for Meteorology and Geodynamics , ZAMG from 1904 ), the world's first independent weather service, with Emperor Franz Joseph . As a result, the station network grew rapidly, from more than 20 observation stations at the end of 1852 to more than 200 stations in 1896 (based on today's federal territory). The two world wars had devastating effects on the density of the station network. After the original climate sheets had been sent to the German Reich Weather Service in Berlin , all the climate sheets were irretrievably destroyed in the hail of bombs on the city in 1944. The number of meteorological stations in Austria soon increased again. Since the 1980s, the conventional, manual weather stations have been gradually replaced by semi-automatic stations.

Today the ZAMG station network comprises around 250 weather stations , which automatically record most meteorological parameters with a high temporal resolution. The data is electronically transmitted to the headquarters and stored in databases. In addition, data recovery activities increase opportunities to study past climates and their variability. This means the backup of climate data, which are stored in paper form in archives, on electronic media.

Most of the time, the raw climate records are not immediately suitable for analyzing climate changes, trends and extreme values. Measurement errors, gaps and inhomogeneities disrupt the measurement series. Therefore, only quality-checked climate series may be used for climate research .

Climate table of selected locations

See also

• Geography of Austria
• Climate classification
• Climate change
• Central Institute for Meteorology and Geodynamics

Web links

• Central Institute for Meteorology and Geodynamics (ZAMG) - Austrian weather and earthquake service
• HISTALP - website with instrumental quality climate data for the greater Alps back to 1760
• Climate change information portal - free range of knowledge on climate change in Austria and the Alpine region

Individual evidence

1. ↑ ^{a b c d e f} Ingeborg Auer u. a .: ÖKLIM - Austria's Digital Climate Atlas. In: Christa Hammerl u. a. (Ed.): The Central Institute for Meteorology and Geodynamics 1851–2001. Leykam, Vienna 2001, ISBN 3-7011-7437-7 .
2. ↑ ^{a b c d e f} Johann Hiebl u. a .: Multi-methodical realization of Austrian climate maps for 1971–2000. In: Advances in Science & Research. No. 6, 2010, pp. 19-26, doi : 10.5194 / asr-6-19-2011 .
3. ↑ Central Institute for Meteorology and Geodynamics: Weather records. Archived copy ( Memento of the original from March 21, 2012 in the Internet Archive ) Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. (March 16, 2012). 
4. ^ University of Vienna: Meteorology: Austria's secret cold pole. Archived copy ( memento of the original dated February 11, 2012 in the Internet Archive ) Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. (March 16, 2012). 
5. ↑ Central Institute for Meteorology and Geodynamics: New heat record: 40.5 ° C in Bad Deutsch-Altenburg. http://www.zamg.ac.at/cms/de/klima/news/neuer-hitze-rekord-40-5deg-c-in-bad-deutsch-altenburg (August 9, 2013).
6. ↑ Anita Jurković u. a .: SON-ALP - interpolations of sunshine duration and global radiation with regard to climate changes in the Alpine region. Central Institute for Meteorology and Geodynamics, Vienna 2010.
7. ↑ ^{a b} Ingeborg Auer u. a .: HISTALP - Historical instrumental climatological surface time series of the greater Alpine region 1760-2003. In: International Journal of Climatology. No. 27, 2007, pp. 17-46, doi : 10.1002 / joc.1377 .
8. ↑ ^{a b} Reinhard Böhm u. a .: A new website with instrumental quality climate data for the greater Alps back to 1760. In: Wiener Mitteilungen. No. 216, 2009, pp. 7–20 ( PDF file; 0.9 MB  ( page no longer available , search in web archives )  Info: The link was automatically marked as defective. Please check the link according to the instructions and then remove it Note. ) ( Online ).  
9. ^ Johann Hiebl, Michael Hofstätter: No increase in multi-day temperature variability in Austria following climate warming. In: Climatic Change , 2012, doi : 10.1007 / s10584-011-0389-x .
10. ↑ Central Institute for Meteorology and Geodynamics: Information portal on climate change. Heavy precipitation: really more floods? Archived copy ( memento of the original dated February 3, 2012 in the Internet Archive ) Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. (March 16, 2012). 
11. ↑ Christoph Matulla and a .: European storminess: late nineteenth century to present. In: Climate Dynamics . No. 29, 2007, doi : 10.1007 / s00382-007-0333-y .
12. ^ University of Innsbruck, Institute for Meteorology and Geophysics: Austrian Glacier Inventory ( online ).
13. ↑ Stephan Gruber, Wilfried Haeberli: Permafrost in steep bedrock slopes and its temperature-related destabilization following climate change. In: Journal of Geophysical Research. No. 112, 2007, F02S18, doi : 10.1029 / 2006JF000547 .
14. ↑ Reinhard Böhm: Snow in Climate Change. Snow and Climate Change. In: Günther Moschig, Wido Sieberer (Ed.): Vom Schnee. On snow. Museum Kitzbühel, Kitzbühel 2008, pp. 60–87 ( PDF file; 1.1 MB  ( page no longer available , search in web archives )  Info: The link was automatically marked as defective. Please check the link according to the instructions and then remove it Note. ).  
15. ↑ Anita Jurković: Total snow depth . Comparative time series analysis. University of Vienna, Vienna 2008.
16. ↑ ^{a b} Ingeborg Auer u. a .: Austrian long-term climate 1767–2000. Multiple instrumental climate time series from Central Europe. In: Austrian contributions to meteorology and geophysics. No. 25. Central Institute for Meteorology and Geodynamics, Vienna 2001 ( PDF file; 3.1 MB ( Memento of the original from February 1, 2012 in the Internet Archive ) Info: The archive link has been inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this note. ).