PL
January 2025 was the warmest in the history of meteorological measurements conducted in Poland, with temperatures significantly above the norm set for the years 1991-2020. Snow appeared sporadically, especially in the lowlands, and rainfall dominated most of the country. IMWM-NRI forecasts indicate a high probability of a mild winter continuing in the coming months, which may affect the hydrological situation, especially in the context of water retention and groundwater levels.
End of the year without precipitation
December last year, in terms of precipitation throughout Poland, was extremely or very dry. The highest monthly precipitation in December recorded in the north of the country was 51 mm in Hel (over 110% of the 1991-2020 multi-year norm), with the highest precipitation recorded in the south in the mountains, on Śnieżka – 71.9 mm (over 63% of the multi-year norm). On the other hand, the lowest monthly precipitation occurred in the West Pomeranian Voivodeship, in the town of Resko – only 7.0 mm, which is less than 11% of the multi-year norm.
The calendar year ended with low water levels prevailing in the Vistula River basin, while the Odra River basin was characterized by average levels, persisting since the September floods.
In most of the country, mainly in the south and east of Poland, a decrease in the average groundwater level was observed compared to the previous months of 2024. In central and western Poland, an increase in the average groundwater level was observed. However, fluctuations in the free groundwater table were usually small (0-0.1 m).
A warm start to the year
The new year began exceptionally warmly in Poland, which is a significant departure from typical winter conditions. According to preliminary analyses by IMWM-NRI, the average air temperature anomaly in January was 3.4°C above the thermal norm for the 1991-2020 multi-year period, while the maximum anomaly reached almost 5.0°C. As a result, positive temperatures prevailed for most days of the month, which mainly resulted in rain or sleet. Snowfall was relatively rare and was mainly limited to periodic phenomena, especially in the south of the country.
Data from IMWM-NRI indicate that the thickest snow cover is currently in the mountains. At Śnieżka station, 70 cm of snow was recorded, in the Valley of Five Lakes – 66 cm, on Kasprowy Wierch – 58 cm, in Jakuszyce – 36 cm, on Śnieżnik – 11 cm, while in Bukowina Tatrzańska and Zakopane the snow cover is only 1 cm.
Currently, water levels in the Vistula and Odra River basins remain mainly in the medium and low zone, which indicates a deepening water deficit. However, elevated water levels have been observed locally, especially on the Bzura and Drwęca (Vistula River basin area) and on the Odra, Bystrzyca, Widawa, Barycz, and Bóbr (Odra River basin area).
In the Lower Odra and West Coast water regions, Pregoła and Niemen, high water levels were recorded only on the Parsęta, while on the remaining rivers, water levels remain in the medium and low range.
Due to the ongoing hydrological drought, hydrological warnings are in force in the catchment areas of Pisa (from January 2, 2025) and Górny Ełk and Górna Legia (from June 20, 2024) – until further notice. Forecasts do not indicate an improvement in the situation in the coming weeks, which raises further concerns about the water balance in regions affected by rainfall deficiency.
Low surface water levels also affect the hydrogeological situation. PGI-NRI issued a warning regarding hydrogeological hazards valid throughout the country from February 1 to February 28, 2025. This means that in the event of a persistent rainfall deficit, further drops in groundwater levels may occur, which on a regional scale may result in the occurrence of a hydrogeological low flow.
Long-term forecasts
According to the latest long-term forecasts published by IMWM-NRI, the average monthly air temperature and total precipitation are predicted to exceed the climate standards for the period 1991-2020 in February. Air temperatures are also expected to be higher than the multi-year averages in March, although precipitation is expected to remain within the norm.
For April, IMWM-NRI forecasts indicate that both the average temperature and total precipitation should be within the range of standards for the 1991-2020 multi-year period. It is worth noting that the current winter is not characterized by low temperatures, typical for this period, and this trend will most likely continue until its end.
Traditionally, in winter, cold air from Siberia flows into Poland, but in recent years, there has been an increasing dominance of milder air masses coming from the west and south, which is changing the face of winter in the country.
IMWM-NRI’s hydrological forecasts for this year assume that water levels may fluctuate in the Vistula and Odra River basins. Water levels will be characterized by a downward trend, stabilization is assumed in the low and medium water zones. On the Coast, on the coastal rivers, fluctuations and periodic increases in water levels are predicted in the medium and high water zones. Forecasts assume a decrease in the shallow groundwater table, below the low warning level. In the event of a precipitation deficit, changes in the level of groundwater reserves will occur. In the eastern part of the country, a situation may arise in which a lack of resource reserves will be observed, in relation to the lowest state of the groundwater table observed for the multi-year period 1991-2020.
However, it should be remembered that the forecasts are subject to change. Depending on the hydrological situation in the country, the analyses based on the models will be updated. This means that the astronomical spring does not have to start accompanied by a hydrological and hydrogeological drought. Nevertheless, current trends indicate that this is a highly probable scenario.
There has been no significant rainfall for a long time, and in most of the country there is no snow cover, which leads to the formation of low water levels and lowering of groundwater levels. The current situation is also influenced by the way water resources are managed – in conditions of low surface and groundwater levels, rational use of water becomes crucial.
Responsible water management is a must – let’s save water, its resources are limited.
