Station 34: Wylfa PS
Figure 'a': Monthly mean surface temperature for the entire
duration of the record at the station which are derived from simple
averaging of all the monthly data.
Figure 'b': Monthly climatic average with the first standard
deviation. The standard deviation has been derived from the
difference in the monthly average from the long-term mean (1971 -
2000).
Figure 'c': Yearly anomaly from the base period. Where the
average base period temperature (1971 - 2000) has been subtracted
from the average annual temperature. The standard deviation of the
annually averaged temperature of the entire record is also shown. A
trend line derived from a linear least squares analysis has been
added to indicate the extent to which annual changes are
linear.
Monthly Mean Sea Temperature for WYLFA POWER
STATION at 53° 25' N, 4° 29' W
| Year |
Jan |
Feb |
Mar |
Apr |
May |
Jun |
Jul |
Aug |
Sep |
Oct |
Nov |
Dec |
mean |
| 1967 |
|
|
|
|
|
|
|
13.9 |
16.0 |
10.9 |
11.0 |
|
|
| 1968 |
7.0 |
6.3 |
6.6 |
7.3 |
9.2 |
12.3 |
14.0 |
|
14.2 |
13.2 |
10.8 |
9.6 |
|
| 1969 |
7.2 |
5.2 |
5.1 |
7.2 |
9.4 |
11.5 |
13.8 |
15.1 |
15.4 |
14.6 |
10.8 |
8.3 |
10.3 |
| 1970 |
7.2 |
6.5 |
6.5 |
7.2 |
10.2 |
12.8 |
13.8 |
14.9 |
14.6 |
13.4 |
11.0 |
8.9 |
10.6 |
| 1971 |
7.8 |
6.9 |
7.1 |
9.0 |
11.1 |
13.2 |
14.8 |
15.4 |
16.5 |
13.5 |
11.3 |
9.9 |
11.4 |
| 1972 |
8.1 |
7.2 |
7.9 |
9.1 |
10.3 |
12.6 |
14.1 |
15.3 |
15.2 |
13.8 |
11.6 |
9.3 |
11.2 |
| 1973 |
8.6 |
8.1 |
8.1 |
8.6 |
10.1 |
12.6 |
14.9 |
15.9 |
15.7 |
13.5 |
11.3 |
9.3 |
11.4 |
| 1974 |
8.6 |
8.4 |
8.2 |
9.4 |
10.8 |
13.2 |
14.9 |
15.8 |
15.0 |
12.5 |
10.3 |
9.5 |
11.4 |
| 1975 |
9.1 |
8.2 |
8.4 |
8.2 |
10.3 |
13.0 |
14.6 |
16.2 |
14.8 |
12.6 |
11.3 |
9.9 |
11.4 |
| 1976 |
9.3 |
6.9 |
7.7 |
9.3 |
11.0 |
13.6 |
16.0 |
16.9 |
15.6 |
14.3 |
11.5 |
8.9 |
11.8 |
| 1977 |
6.8 |
7.3 |
7.6 |
8.6 |
10.9 |
13.1 |
15.2 |
16.1 |
15.5 |
14.4 |
10.6 |
9.5 |
11.3 |
| 1978 |
8.3 |
6.9 |
8.0 |
8.3 |
10.5 |
12.9 |
13.9 |
14.8 |
14.8 |
14.0 |
12.8 |
10.1 |
11.3 |
| 1979 |
7.1 |
5.6 |
6.3 |
7.5 |
9.0 |
11.9 |
13.6 |
14.8 |
14.9 |
13.9 |
11.3 |
9.4 |
10.4 |
| 1980 |
7.3 |
7.2 |
7.6 |
9.1 |
11.1 |
13.3 |
14.3 |
15.2 |
15.3 |
13.8 |
10.6 |
8.5 |
11.1 |
| 1981 |
8.1 |
7.6 |
7.7 |
9.3 |
10.2 |
12.8 |
14.4 |
16.0 |
15.6 |
13.3 |
11.1 |
9.0 |
11.3 |
| 1982 |
6.3 |
7.3 |
8.0 |
9.1 |
10.6 |
13.1 |
14.6 |
16.2 |
15.8 |
14.5 |
12.2 |
9.4 |
11.4 |
| 1983 |
8.8 |
7.4 |
7.7 |
8.3 |
9.8 |
11.0 |
14.2 |
15.6 |
14.9 |
13.6 |
11.4 |
9.8 |
11.0 |
| 1984 |
8.3 |
7.2 |
7.0 |
8.4 |
10.4 |
12.6 |
14.7 |
16.3 |
15.6 |
14.1 |
11.7 |
9.2 |
11.3 |
| 1985 |
7.3 |
5.9 |
6.3 |
7.4 |
8.9 |
12.0 |
14.0 |
14.2 |
14.4 |
13.6 |
10.7 |
9.2 |
10.3 |
| 1986 |
7.6 |
5.8 |
5.7 |
6.8 |
9.9 |
12.2 |
14.3 |
14.8 |
13.7 |
13.8 |
11.1 |
9.7 |
10.5 |
| 1987 |
7.1 |
7.0 |
7.1 |
9.0 |
10.9 |
12.9 |
14.9 |
15.8 |
16.0 |
13.9 |
12.0 |
9.9 |
11.4 |
| 1988 |
8.9 |
7.3 |
8.0 |
9.0 |
10.8 |
13.3 |
14.8 |
15.7 |
15.2 |
14.1 |
13.2 |
10.7 |
11.8 |
| 1989 |
8.8 |
8.0 |
7.8 |
8.4 |
10.4 |
12.9 |
15.0 |
15.9 |
15.2 |
14.2 |
11.5 |
9.1 |
11.4 |
| 1990 |
8.8 |
7.9 |
7.5 |
8.0 |
10.4 |
12.4 |
14.3 |
15.7 |
15.6 |
13.7 |
11.5 |
8.8 |
11.2 |
| 1991 |
6.9 |
5.8 |
6.9 |
8.2 |
10.1 |
11.5 |
15.0 |
15.9 |
16.0 |
14.1 |
11.5 |
9.6 |
11.0 |
| 1992 |
8.8 |
7.9 |
8.0 |
8.5 |
11.0 |
12.8 |
14.9 |
15.7 |
14.8 |
13.2 |
10.8 |
9.6 |
11.3 |
| 1993 |
7.8 |
7.3 |
7.3 |
8.5 |
10.9 |
13.0 |
14.5 |
15.3 |
14.6 |
11.6 |
9.9 |
8.0 |
10.7 |
| 1994 |
7.5 |
5.9 |
7.5 |
8.5 |
10.0 |
13.0 |
15.0 |
15.5 |
14.0 |
13.0 |
12.0 |
9.8 |
11.0 |
| 1995 |
7.9 |
7.8 |
8.0 |
8.5 |
11.0 |
14.0 |
16.0 |
16.9 |
16.0 |
14.0 |
12.0 |
8.0 |
11.7 |
| 1996 |
6.0 |
6.0 |
6.5 |
8.0 |
11.5 |
12.5 |
15.5 |
15.6 |
14.5 |
13.5 |
9.5 |
|
|
| 1997 |
6.5 |
7.8 |
8.2 |
10.0 |
12.0 |
13.5 |
15.5 |
16.5 |
14.5 |
13.0 |
11.5 |
10.0 |
11.6 |
| 1998 |
8.5 |
8.5 |
9.0 |
11.0 |
12.0 |
12.0 |
15.0 |
16.0 |
15.0 |
13.0 |
11.0 |
9.0 |
11.7 |
| 1999 |
8.0 |
7.0 |
8.5 |
10.5 |
11.0 |
14.0 |
15.0 |
16.5 |
16.0 |
13.0 |
11.0 |
9.0 |
11.6 |
| 2000 |
8.0 |
7.5 |
8.0 |
9.0 |
10.5 |
12.5 |
14.5 |
16.5 |
14.5 |
12.5 |
11.5 |
8.5 |
11.1 |
| 2001 |
8.0 |
7.0 |
7.5 |
8.5 |
11.0 |
14.0 |
15.5 |
16.0 |
15.0 |
10.5 |
12.0 |
10.0 |
11.3 |
| 2002 |
8.5 |
8.0 |
8.0 |
9.0 |
11.0 |
13.0 |
14.0 |
16.0 |
15.5 |
15.0 |
11.0 |
9.5 |
11.5 |
| 2003 |
8.0 |
7.0 |
8.0 |
9.0 |
11.0 |
14.0 |
15.0 |
17.0 |
17.0 |
14.0 |
13.0 |
10.0 |
11.9 |
| 2004 |
8.0 |
7.0 |
7.5 |
8.5 |
10.0 |
13.0 |
14.5 |
16.5 |
15.5 |
14.0 |
13.0 |
11.0 |
11.5 |
| 2005 |
9.0 |
8.0 |
8.5 |
8.5 |
11.0 |
12.0 |
14.5 |
16.0 |
16.5 |
14.8 |
14.8 |
11.0 |
12.1 |
| 2006 |
9.0 |
8.0 |
7.0 |
8.0 |
10.0 |
12.0 |
15.0 |
16.0 |
16.0 |
15.5 |
13.0 |
11.0 |
11.7 |
| 2007 |
9.0 |
7.5 |
8.5 |
8.5 |
10.5 |
12.0 |
15.0 |
16.0 |
16.5 |
15.0 |
14.0 |
11.0 |
12.0 |
| whole data set |
| mean |
7.9 |
7.2 |
7.5 |
8.6 |
10.5 |
12.8 |
14.7 |
15.8 |
15.3 |
13.6 |
11.6 |
9.5 |
|
| count |
40 |
40 |
40 |
40 |
40 |
40 |
40 |
40 |
41 |
41 |
41 |
39 |
|
| sd |
0.84 |
0.83 |
0.81 |
0.85 |
0.69 |
0.71 |
0.57 |
0.69 |
0.73 |
1.00 |
1.04 |
0.77 |
|
| 1971 - 2000 |
| mean |
7.9 |
7.2 |
7.6 |
8.7 |
10.6 |
12.8 |
14.7 |
15.8 |
15.2 |
13.5 |
11.3 |
9.3 |
|
| count |
30 |
30 |
30 |
30 |
30 |
30 |
30 |
30 |
30 |
30 |
30 |
29 |
|
| sd |
0.87 |
0.81 |
0.72 |
0.85 |
0.70 |
0.67 |
0.56 |
0.63 |
0.66 |
0.66 |
0.76 |
0.61 |
|
Source: BNFL, CEGB