19 
on 30 March, minimum temperatures of about -8°C were recorded. Water temperatures in 
Trzebiez fell from 8.3°C on 25 March to 4.6°C on 30 March. 
Table 2.4. Air temperatures and variations from the normal value (1961-1990) 
in Szczecin Lagoon in winter season 1976/77 
November 
December 
January 
February 
March 
mean 
max. 
min. 
mean 
max. 
min. 
mean 
max. 
min. 
mean 
max. 
min. 
mean 
max. 
min. 
Swinoujscie 
5.5 
13.9 
-1.7 
-0.1 
9.5 
-11.7 
-0.2 
8.6 
-7.1 
1.3 
10.9 
-5.5 
4.5 
15.4 
-4.9 
divergence 
0.8 
- 1.2 
0.4 
1.4 
1.9 
Trzebiez 
5.1 
15.2 
-4.4 
-0.4 
10.0 
-15.6 
-0.2 
9.6 
-7.1 
1.3 
11.0 
-6.3 
4.9 
17.1 
-7.7 
divergence 
0.8 
- 1.2 
0.8 
1.7 
2.3 
Szczecin 
5.2 
16.3 
-3.5 
-0.6 
10.2 
-17.2 
-0.2 
10.1 
-8.0 
1.5 
11.6 
-6.8 
5.4 
16.8 
-8.3 
divergence 
0.8 
- 1.4 
0.9 
1.9 
2.4 
Table 2.5. Water temperatures and variations from the normal value (1961-1990) 
in Szczecin Lagoon in winter season 1976/77 
November 
December 
January 
February 
March 
mean 
max. 
min. 
mean 
max. 
min. 
mean 
max. 
min. 
mean 
max. 
min. 
mean 
max. 
min. 
Miedzyzdroje** 
6.0 
7.5 
4.0 
2.4 
5.0 
-0.2 
0.2 
0.9 
-0.2 
0.7 
1.9 
0.0 
3.0 
4.5 
i.i 
divergence 
-0.4 
- 0.3 
-0.9 
-0.3 
0.8 
Swinoujscie 
6.2 
8.0 
4.2 
1.9 
4.4 
0.0 
0.4 
1.4 
0.0 
1.0 
2.5 
0.2 
5.4 
7.8 
2.0 
divergence 
0.1 
- 0.5 
- 0.7 
-0.2 
2.7 
Trzebiez 
5.8 
7.0 
2.8 
1.7 
5.4 
0.1 
0.3 
1.5 
0.0 
1.7 
4.4 
0.1 
6.2 
8.3 
2.9 
divergence 
0.4 
-0.4 
- 0.8 
0.4 
2.8 
Szczecin 
6.8 
8.2 
4.5 
2.6 
5.5 
0.3 
0.7 
1.7 
0.2 
2.5 
4.8 
1.2 
6.7 
8.8 
2.9 
divergence 
0.6 
0.0 
-0.8 
0.7 
2.4 
* - channel, 
** - sea 
2.2.2. Characteristics of the 1976/77 ice season in the areas of Szczecin Lagoon and 
Pomeranian Bay 
First ice formed in sheltered areas on the edges of Szczecin Lagoon after about a week of light 
frost between 25 and 28 December. Ice formation in the fairway Szczecin - Swinoujscie and 
the central part of Szczecin Lagoon started on 29 December, and on 30 December it was 
covered with thin fast ice. Its thickness increased relatively quickly in the following week. 
The Pomeranian Bay, apart from some minor new ice formation between 11 and 22 January 
in its southern part, remained ice-free. 
In Szczecin Lagoon, the ice started to melt after 20 February and had disappeared completely 
by 6 March. 
In the winter of 1976/77, ice was observed in Szczecin Lagoon on about 60 days, in the 
Pomeranian Bay on three days. 
Maximum ice extent was reached around 20 January (Figure 2.3a). The maximum thickness 
of level fast ice measured in Szczecin Lagoon in this time was 15-30 cm, up to 5 cm thick 
new ice occurred in places along the southern coast of the Pomeranian Bay. 
In the moderate ice winter of 1971/72 (example in the Figure 2.3b), the thickness of level ice 
in the Szczecin Lagoon reached values between 20 and 35 cm. The navigation east of the 
islands RUgen and Usedom was obstructed on about 12 days by belts of close, partly rafted 
10-20 cm thick drift ice.