Figure 1.
Location of the analysed meteorological stations.
Table 1.
The coincidence of the beginning of the meteorological and thermal seasons, with up to five days’ variation (the number of occurrences between 1951 and 2020)
| station | spring | summer | autumn | winter | station | spring | summer | autumn | winter |
|---|---|---|---|---|---|---|---|---|---|
| BIAŁYSTOK | 12 | 53 | 60 | 68 | POZNAŃ | 27 | 57 | 51 | 68 |
| BIELSKO-BIAŁA | 33 | 52 | 51 | 65 | SANDOMIERZ | 25 | 57 | 46 | 69 |
| CHOJNICE | 15 | 53 | 63 | 68 | SIEDLCE | 18 | 58 | 55 | 68 |
| CZĘSTOCHOWA | 28 | 56 | 51 | 68 | SŁUBICE | 37 | 56 | 51 | 63 |
| GORZÓW | 30 | 58 | 48 | 68 | SUWAŁKI | 6 | 54 | 61 | 68 |
| JELENIA GÓRA | 27 | 45 | 66 | 68 | ŚWINOUJŚCIE | 29 | 47 | 45 | 63 |
| KALISZ | 25 | 56 | 46 | 68 | SZCZECIN | 32 | 55 | 49 | 65 |
| KIELCE | 23 | 53 | 53 | 68 | TARNÓW | 32 | 56 | 45 | 66 |
| KOSZALIN | 25 | 49 | 56 | 66 | TORUŃ | 25 | 57 | 52 | 68 |
| LUBLIN | 19 | 53 | 56 | 69 | WARSZAWA | 25 | 57 | 49 | 68 |
| ŁEBA | 12 | 40 | 55 | 67 | WŁODAWA | 18 | 59 | 52 | 69 |
| ŁÓDŹ | 21 | 56 | 52 | 68 | WROCŁAW | 33 | 57 | 45 | 67 |
| OLSZTYN | 17 | 53 | 55 | 68 | ZAKOPANE | 13 | 29 | 69 | 69 |
| OPOLE | 34 | 59 | 46 | 68 | ZIELONA GÓRA | 32 | 56 | 55 | 66 |
| PŁOCK | 23 | 55 | 47 | 68 | |||||
Figure 2.
Duration of thermal spring for nine selected stations [days]
Source: own study
Figure 3.
The mean values of seasonal air temperatures in 1951–2020 [°C]
Source: own study
Table 2.
The average differences between the temperatures of meteorological seasons and those of thermal and calendar seasons in 1951–2020 [°C]
| meteorological season | vs. thermal | vs. calendar |
|---|---|---|
| winter | +0.1 (West) to +0.4 (East) | +0.3 whole area |
| spring | +1.0 (West) to +2.5 (East) | +3–3.5 whole area |
| summer | +0.2 whole area | −0.5 whole area |
| autumn | −0.2 to −0.4 depending on the region | −3.0 whole area |
Figure 4.
The mean values of spring air temperatures in 1951–2020 [°C]
Source: own study
Figure 5.
The mean values of autumn air temperatures in 1951–2020 [°C]
Source: own study
Figure 6.
The seasonal sum of precipitation for 1952–2020 [mm] Source: own study
Table 3.
The average differences between the seasonal precipitation for meteorological seasons and those of thermal and calendar seasons in 1951–2020 [mm]
| meteorological season | vs. thermal | vs. calendar |
|---|---|---|
| winter | +10 | −10 |
| spring | − 5 | + a dozen to several dozen |
| summer | − 1 to −5 | - several to − 20-odd |
| autumn | − 4 | - a dozen to − 20 |
Figure 7.
The seasonal sum of winter precipitation in 1952–2020 [mm]
Source: own study
Figure 8.
The seasonal sum of spring precipitation in 1951–2020 [mm]
Source: own study
Figure 9.
(a) Mean winter temperature in Sandomierz and (b) mean spring temperature in Siedlce. Dotted lines – linear regression-
Source: own study
Figure 10.
Temperature change in spring (1951–2020)
Source: own study
Figure 11.
Mean seasonal temperature (1951–2020): (a) summer in Gorzów and (b) autumn in Kalisz. Dotted lines – linear regression
Source: own study
Figure 12.
Precipitation change in winter (1952–2020)
Source: own study
Figure 13.
Precipitation change in spring (1951–2020)
Source: own study