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Fig. 5.
Annual and monthly values making the multi-annual trend (1951–2020) and 10-year Universal Thermal Climate Index measured at 12:00 UTC in Kołobrzeg, Poznań and Kraków_ Values with a statistical significance level of 0_05 are marked in bold type_
| City | Kołobrzeg | Poznań | Kraków | |||
|---|---|---|---|---|---|---|
| Month | 1951–2020 | per 10 years | 1951–2020 | per 10 years | 1951–2020 | per 10 years |
| 1 | 5.4 | 0.8 | 4.8 | 0.7 | 3.6 | 0.5 |
| 2 | 6.6 | 0.9 | 5.3 | 0.8 | 6.8 | 1.0 |
| 3 | 7.3 | 1.0 | 6.6 | 0.9 | 7.0 | 1.0 |
| 4 | 6.1 | 0.9 | 7.6 | 1.1 | 5.9 | 0.8 |
| 5 | 5.8 | 0.8 | 5.1 | 0.7 | 5.3 | 0.8 |
| 6 | 3.9 | 0.6 | 2.2 | 0.3 | 3.9 | 0.6 |
| 7 | 4.3 | 0.6 | 4.7 | 0.7 | 4.5 | 0.6 |
| 8 | 5.2 | 0.7 | 5.2 | 0.7 | 4.8 | 0.7 |
| 9 | 4.0 | 0.6 | 2.1 | 0.3 | 1.9 | 0.3 |
| 10 | 3.5 | 0.5 | 1.6 | 0.2 | 2.5 | 0.4 |
| 11 | 5.6 | 0.8 | 4.4 | 0.6 | 3.8 | 0.5 |
| 12 | 4.3 | 0.6 | 3.2 | 0.5 | 2.8 | 0.4 |
| year | 5.2 | 0.7 | 4.4 | 0.6 | 4.4 | 0.6 |
Thermal stress categories based on the Universal Thermal Climate Index (Błażejczyk et al_ 2010)_
| UTCI (°C) | Stress category and recommendations for protection |
|---|---|
| > 46.0 | extreme heat stress, periodical cooling and drinking > 0.5 l • h–1 necessary, stay without activity |
| 38.1 to 46.0 | very strong heat stress, periodical use of air conditioning or shaded sites and drinking > 0.5 l • h–1 necessary, reduce activity |
| 32.1 to 38.0 | strong heat stress, drinking> 0.25 l • h–1 necessary, use shade places and reduce activity |
| 26.1 to 32.0 | moderate heat stress, drinking> 0.25 l • h–1 necessary |
| 9.1 to 26.0 | no thermal stress, physiological thermoregulation sufficient to keep comfort |
| 0.1 to 9.0 | slight cold stress, use gloves and cap |
| −13.0 to 0.0 | moderate cold stress, increase activity, protect extremities and face against cooling |
| −27.0 to −12.9 | strong cold stress, strongly increase activity, protect face and extremities, use better insulated clothing |
| −40.0 to −26.9 | very strong cold stress, strongly increase activity, protect face and extremities, use better insulated clothing, reduce stay outdoor |
| < −40.0 | extreme cold stress, stay in door or use heavy, wind protected clothing |
Annual and monthly linear trend values recorded at 12:00 UTC for the frequency of respective types of thermal stress in Kołobrzeg, Poznań and Kraków (1951–2020)_ Values with a statistical significance level 0_05 are marked in bold type_
| Month | Extreme, very strong and strong cold stress | Moderate and slight cold stress | No thermal stress | Moderate heat stress | Strong and very strong heat stress |
|---|---|---|---|---|---|
| Kołobrzeg | |||||
| 1 | −30.7 | 30.9 | 2 cases | – | – |
| 2 | −33.4 | 32.3 | 1.1 | – | – |
| 3 | −27.0 | 21.9 | 5.2 | – | – |
| 4 | −8.4 | −14.5 | 22.3 | 0.4 | 1 case |
| 5 | −1.1 | −29.1 | 26.6 | 3.3 | 0.3 |
| 6 | – | −12.8 | 5.8 | 5.3 | 1.7 |
| 7 | – | −6.7 | −11.8 | 15.5 | 2.9 |
| 8 | – | −11.3 | −7.2 | 14.6 | 3.9 |
| 9 | 3 cases | −17.4 | 13.7 | 4.4 | −0.4 |
| 10 | −0.6 | −17.6 | 18.7 | −0.5 | – |
| 11 | −14.4 | 9.2 | 5.2 | – | – |
| 12 | −18.3 | 18.7 | −0.4 | – | – |
| year | −11.1 | 0.1 | 6.5 | 3.6 | 0.8 |
| Poznań | |||||
| 1 | −26.4 | 26.0 | 0.4 | – | – |
| 2 | −28.8 | 28.3 | 0.4 | – | – |
| 3 | −29.8 | 24.1 | 5.8 | – | – |
| 4 | −12.3 | −9.8 | 21.4 | 0.8 | 1 case |
| 5 | −1.3 | −19.5 | 16.9 | 3.9 | 0.2 |
| 6 | – | −9.1 | 5.2 | −1.3 | 5.3 |
| 7 | – | −12.7 | −1.3 | 8.0 | 6.0 |
| 8 | – | −14.3 | −4.1 | 13.9 | 4.5 |
| 9 | 1 case | −11.6 | 13.0 | −0.7 | −0.6 |
| 10 | −1.4 | 0.9 | 0.7 | −0.3 | – |
| 11 | −13.9 | 10.5 | 3.4 | – | – |
| 12 | −20.9 | 20.9 | 0.0 | – | – |
| year | −11.2 | 2.7 | 5.1 | 2.1 | 1.3 |
| Kraków | |||||
| 1 | −13.8 | 11.5 | 2.3 | – | – |
| 2 | −21.9 | 12.5 | 9.5 | – | – |
| 3 | −17.0 | 3.8 | 13.4 | −0.2 | – |
| 4 | −1.8 | −20.1 | 17.6 | 4.0 | 0.4 |
| 5 | – | −20.1 | 5.2 | 11.4 | 3.5 |
| 6 | – | −7.9 | −10.6 | 9.0 | 9.5 |
| 7 | – | −3.9 | −19.1 | 7.2 | 15.8 |
| 8 | – | −2.4 | −22.8 | 4.9 | 20.3 |
| 9 | – | −7.9 | 2.5 | 6.4 | −1.0 |
| 10 | −0.6 | −5.8 | 0.5 | 6.0 | – |
| 11 | −4.5 | −7.7 | 12.3 | 1 case | – |
| 12 | −9.8 | 5.6 | 4.2 | – | – |
| year | −5.7 | −3.6 | 1.1 | 4.1 | 4.1 |