Fig. 1
Location of the weather stations.
Table 1
Cities included in the study, their geographic location, area and population in 2019 (GUS 2020).
| City | Altitude | Latitude | Longitude | Area | Population |
|---|---|---|---|---|---|
| [m a.s.l.] | [degree] | [km2] | x 103 | ||
| Białystok | 148 | 53°06′26″ | 23°09′44″ | 102 | 297.6 |
| Gorzów | 72 | 52°44′28″ | 15°16′38″ | 86 | 123.6 |
| Katowice | 278 | 50°14′26″ | 19°01′58″ | 165 | 292.8 |
| Kielce | 260 | 50°48′38″ | 20°41′32″ | 110 | 194.9 |
| Kraków | 237 | 50°04′40″ | 19°47′42″ | 327 | 779.1 |
| Lublin | 193 | 51°13′00″ | 22°23′35″ | 148 | 339.8 |
| Łódź | 180 | 51°43′06″ | 19°23′14″ | 293 | 679.9 |
| Poznań | 88 | 52°25′00″ | 16°50′05″ | 262 | 534.8 |
| Toruń | 69 | 53°02′31″ | 18°35′44″ | 116 | 201.4 |
| Warszawa | 106 | 52°09′46″ | 20°57′40″ | 517 | 1790.7 |
| Lesko | 420 | 49°27′59″ | 22°20′30″ | 15 | 5.4 |
Fig. 2
Proportion of impervious surfaces in Poland by communes in (A) 1990, (B) 2000, (C) 2010 and (D) 2020.
Fig. 3
Changes in the imperviousness index in Poland in percentage points (pp) by communes in 1990–2020.
Fig. 4
Bartoszyce – before and after revitalisation.
Table 2
Changes in impervious surface (IS) in Poland in the years 1991–2020.
| Index | 1991 | 2001 | 2011 | 2020 |
|---|---|---|---|---|
| ISs in km2 – municipalities | 3093 | 3199 | 3445 | 3475 |
| ISs in km2 – rural communes | 2479 | 2652 | 2976 | 3517 |
| ISs in km2 – municipal–rural communes | 2109 | 2218 | 2445 | 2762 |
| ISs in km2 – total | 7682 | 8069 | 8866 | 9954 |
| ISs share in % – total | 2.46 | 2.58 | 2.84 | 3.2 |
| Average annual growth in % – total | 0.51 | 0.99 | 1.63 | |
| Increase in % – total | 5.1 | 9.9 | 16.3 | |
| Total for the years 1991–2020 | 29.9 | |||
Table 3
Proportion (%) of changes in impervious surface in selected cities in Poland in the years 1991–2020 in percentage points.
| City | Imperviousness index | Change [%] | |||||
|---|---|---|---|---|---|---|---|
| 1991 | 2001 | 2011 | 2020 | 1991–2000 | 2001–2010 | 2011–2020 | |
| Białystok | 38.1 | 40.4 | 43.5 | 47.2 | 2.3 | 3.1 | 3.7 |
| Gorzów | 25.5 | 26.1 | 29.4 | 31.4 | 0.6 | 3.3 | 2.0 |
| Katowice | 32.2 | 32.3 | 34.1 | 34.9 | 0.1 | 1.8 | 0.8 |
| Kielce | 28.6 | 29.0 | 31.2 | 32.3 | 0.4 | 2.2 | 1.1 |
| Kraków | 32.3 | 32.7 | 36.6 | 37.5 | 0.4 | 3.9 | 0.9 |
| Lublin | 29.4 | 31.5 | 34.4 | 37.6 | 2.1 | 2.9 | 3.2 |
| Łódź | 32.4 | 32.7 | 34.4 | 36.2 | 0.3 | 1.7 | 1.8 |
| Poznań | 35.4 | 36.3 | 38.8 | 41.3 | 0.9 | 2.5 | 2.5 |
| Toruń | 28.0 | 29.3 | 32.9 | 34.8 | 1.3 | 3.6 | 1.9 |
| Warszawa | 41.9 | 43.2 | 46.7 | 47.5 | 1.3 | 3.5 | 0.9 |
| Lesko | 1.1 | 1.2 | 1.3 | 1.5 | 0.1 | 0.1 | 0.2 |
Fig. 5
The average (A) maximum air temperature, (B) low-level cloud cover and (C) relative humidity in the warm part of the year (April–September) in the period 1991–2020.
Fig. 6
The magnitude (slope value) and statistical significance of linear trends of (A) maximum air temperature, (B) low-level cloud cover and (C) relative humidity in the warm part of the year (April–September of 1991–2020).
Fig 7
The slope of increase in average air temperature and decrease in relative air humidity in the period 2001–2020 compared to the years 1981–2000 at various altitudes in the troposphere (averaged values for Poland).
Table 4
The linear temporal trend slopes of the average area-wise values of air temperature and relative humidity at 2 m AGL and at different isobaric levels in Poland in the years 1981–2020.
Fig. 8
The multi-annual variability of the average (A) maximum air temperature, (B) low-level cloud cover and (C) relative humidity in the warm part of the year (1991–2020) in the selected areas.
Fig 9
Percentage magnitude of changes in the maximum temperature, low-level cloudiness and relative air humidity between the decades (averaged values for the 10 cities).
Table 5
The average maximum temperature Tmax in individual decades and the magnitude of its changes in the areas of the analysed cities in the warm part of the year (April–September).
| City | Average Tmax | Change | |||||
|---|---|---|---|---|---|---|---|
| 1981–1990 | 1991–2000 | 2001–2010 | 2011–2020 | 1991–2000 compared to 1981–1990 | 2001–2010 compared to 1991–2000 | 2011–2020 compared to 2001–2010 | |
| [°C] | [%] | ||||||
| Białystok | 19.8 | 20.5 | 21.3 | 21.6 | +3.4 | +4.0 | +1.6 |
| Gorzów | 19.7 | 20.4 | 21.2 | 21.5 | +3.1 | +3.9 | +1.5 |
| Katowice | 19.8 | 20.4 | 21.2 | 21.6 | +3.1 | +3.6 | +2.2 |
| Kielce | 19.5 | 20.1 | 21.1 | 21.6 | +3.0 | +4.4 | +2.5 |
| Kraków | 20.0 | 20.7 | 21.5 | 21.9 | +3.5 | +3.8 | +1.9 |
| Lublin | 19.2 | 19.7 | 20.6 | 21.2 | +2.7 | +4.5 | +2.6 |
| Łódź | 19.8 | 20.2 | 21.0 | 21.5 | +1.8 | +4.3 | +2.2 |
| Poznań | 20.0 | 20.6 | 21.5 | 21.8 | +2.9 | +4.5 | +1.5 |
| Toruń | 20.0 | 20.5 | 21.2 | 21.8 | +2.8 | +3.5 | +2.5 |
| Warszawa | 20.0 | 20.3 | 21.2 | 21.8 | +1.9 | +4.4 | +2.7 |
| Lesko | 18.6 | 19.3 | 20.0 | 20.7 | +3.8 | +3.6 | +3.3 |
Table 6
Average low-level cloudiness in individual decades and the magnitude of its changes in the analysed cities in the warm part of the year (April–September).
| City | Average low-level cloudiness (%) | Change | |||||
|---|---|---|---|---|---|---|---|
| 1981–1990 | 1991–2000 | 2001–2010 | 2011–2020 | 1991–2000 compared to 1981–1990 | 2001–2010 compared to 1991–2000 | 2011–2020 compared to 2001–2010 | |
| [%] | [%] | ||||||
| Białystok | 47.6 | 47.9 | 46.2 | 45.6 | +0.5 | −3.6 | −1.2 |
| Gorzów | 48.4 | 49.0 | 43.9 | 40.6 | +1.2 | −10.9 | −7.9 |
| Katowice | 47.0 | 47.9 | 46.2 | 45.5 | +1.8 | −3.6 | −1.5 |
| Kielce | 46.8 | 46.2 | 42.4 | 39.4 | −1.3 | −8.5 | −7.5 |
| Kraków | 44.1 | 42.3 | 40.0 | 39.0 | −4.3 | −5.5 | −2.6 |
| Lublin | 45.7 | 44.7 | 42.6 | 41.4 | −2.1 | −4.8 | −2.6 |
| Łódź | 45.0 | 46.2 | 43.1 | 41.7 | +2.6 | −7.0 | −3.2 |
| Poznań | 44.0 | 43.5 | 40.7 | 39.9 | −1.0 | −6.7 | −2.1 |
| Toruń | 48.1 | 47.9 | 43.0 | 42.2 | −0.5 | −10.8 | −1.9 |
| Warszawa | 48.1 | 47.9 | 43.0 | 42.2 | −4.2 | −5.5 | −2.9 |
| Lesko | 54.4 | 54.6 | 52.4 | 48.0 | +0.8 | −4.0 | −8.8 |
Table 7
Average relative air humidity in individual decades and the magnitude of its changes in the area of the analysed cities in the warm part of the year (April–September).
| City | Mean f | Change | |||||
|---|---|---|---|---|---|---|---|
| 1981–1990 | 1991–2000 | 2001–2010 | 2011–2020 | 1991–2000 compared to 1981–1990 | 2001–2010 compared to 1991–2000 | 2011–2020 compared to 2001–2010 | |
| [%] | [%] | ||||||
| Białystok | 73.7 | 73.2 | 71.7 | 70.5 | –0.6 | –2.1 | –1.6 |
| Gorzów | 72.8 | 72.6 | 70.1 | 67.8 | –0.2 | –3.6 | –3.3 |
| Katowice | 73.7 | 73.2 | 71.7 | 70.5 | –0.6 | –2.1 | –1.6 |
| Kielce | 76.7 | 76.6 | 74.0 | 73.0 | –0.1 | –3.4 | –1.4 |
| Kraków | 75.7 | 74.8 | 73.4 | 72.5 | –1.2 | –1.9 | –1.2 |
| Lublin | 77.0 | 76.3 | 73.7 | 72.6 | –0.9 | –3.5 | –1.4 |
| Łódź | 74.9 | 74.8 | 70.3 | 70.1 | –0.1 | –6.2 | –0.3 |
| Poznań | 72.5 | 72.4 | 68.6 | 66.9 | –0.2 | –5.3 | –2.6 |
| Toruń | 73.6 | 72.1 | 70.1 | 68.9 | –2.0 | –2.8 | –1.7 |
| Warszawa | 74.7 | 74.6 | 70.1 | 67.6 | –0.2 | –6.2 | –3.7 |
| Lesko | 78.7 | 78.2 | 77.7 | 76.0 | –0.6 | –0.6 | –2.2 |
Fig. 10
The quantile classification of the frequency of occurrence of certain types of clouds (averaged values for the 10 cities).