The climate of the Jeseníky Mountains and its development
Authors:   Český hydrometeorologický ústav, Lipina Pavel , Šustková Veronika ,   Český hydrometeorologický ústav
Published: January 2025

The mountainous relief of the terrain has a significant effect especially on the temperature and precipitation characteristics. They mainly occur on windward slopes (mainly south-west to west), in the summer months, under conditions for convective weather manifestations, often accompanied by the formation of massive storm clouds, the appearance of intense precipitation and also storms. The relief of the Jeseníky Mountains, with high hills and narrow valleys, results in frequent occurrence of ground temperature inversions. Under suitable conditions, especially with clear night sky in spring and autumn, valley fogs arise resulting in lowering significantly air temperature before dawn. In most of the territory of Hrubý Jeseník Mountains and the massif of the Králický Sněžník climatological characteristics are dominantly influenced in relation to the altitude. For climatological processing and climate characteristics, we have defined the Jeseníky Mountain area, which is primarily based on geomorphological units. The area of the defined territory of the Jeseníky Mountains is approximately 3,251 square kilometres, which is approximately 4% of the territory of the Czech Republic. The average altitude is 613.1 meters above sea level. We calculated the area monthly and annual characteristics for the Jeseníky Mountains for the main processed meteorological elements, i.e. average monthly air temperature, monthly precipitation, monthly sunshine duration and in winter also for the monthly amount of new snow. Time series included air temperature and precipitation since 1875, new snow since 1896, and sunshine duration since 1932. The average annual air temperature for the normal period, or normal 1991–2020, is 7.2 °C. The highest average annual air temperature in the Jeseníky Mountain was 8.4 °C in 2019. According to the average annual air temperature (4.4 °C) in the Jeseníky Mountains, the year 1875 and 1940 were the coldest. Based on the evaluation of the linear trend, the average temperature has increased over the last 150 years annual air temperature in the Jeseníky Mountains by 1.5 °C. On average, the air temperature increases the most in November, by almost 2.2 °C in 150 years, and the least in September (by 0.7 °C). The average annual precipitation total for the defined area of the Jeseníky Mountains is 848.7mm. The highest annual precipitation total, 1,217.8mm, was recorded in 1890. The year 2015 was the lowest in terms of precipitation, with only 590mm of precipitation. In almost 150 years, the annual precipitation has decreased by around 77mm. The largest long-term decrease in precipitation is evident in October, almost 23mm in 150 years, and the lowest in February, August and December (between 2–3 mm). In the top parts of the Jeseníky Mountains, if the snow has not been blown, around 540cm snow cover occurs on an annual average. At the altitude of 1,300m above sea level, the annual total is around 460cm. Altitude zones around 1,100m above sea level have an average annual depth of new snow approximately 390cm. In areas around 1,000m above sea level, an average of 350cm of new snow cover appears in the Jeseníky Mountains. In the published literature, we searched for significant episodes related to the weather and climate of the Jeseníky Mountains, which we supplemented with data on the values of individual meteorological elements from local stations.