BIRR |
monthly
and annual mean and extreme values |
1961-1990 |
|
TEMPERATURE (degrees Celsius) |
jan |
feb |
mar |
apr |
may |
jun |
jul |
aug |
sep |
oct |
nov |
dec |
year |
mean daily max. |
7.5 |
7.9 |
9.8 |
12.2 |
14.9 |
17.7 |
19.2 |
18.8 |
16.6 |
13.6 |
9.7 |
8.2 |
13.0 |
mean daily min. |
1.8 |
1.8 |
2.5 |
3.5 |
5.9 |
8.7 |
10.7 |
10.3 |
8.5 |
6.7 |
3.1 |
2.5 |
5.5 |
mean |
4.6 |
4.8 |
6.1 |
7.9 |
10.4 |
13.2 |
14.9 |
14.6 |
12.6 |
10.1 |
6.4 |
5.4 |
9.3 |
absolute max. |
13.8 |
15.0 |
19.7 |
23.7 |
25.7 |
31.2 |
30.8 |
29.3 |
24.5 |
22.3 |
17.5 |
15.3 |
31.2 |
absolute min. |
-14.6 |
-10.5 |
-10.5 |
-4.6 |
-2.2 |
-0.3 |
3.1 |
1.2 |
-1.0 |
-3.4 |
-7.2 |
-9.4 |
-14.6 |
mean no. of days with
air frost |
9.0 |
7.7 |
7.0 |
4.2 |
1.0 |
0.1 |
0.0 |
0.0 |
0.3 |
1.5 |
7.1 |
7.8 |
45.7 |
mean no. of days with
ground frost |
17.0 |
15.1 |
13.6 |
11.8 |
6.1 |
1.2 |
0.1 |
0.2 |
2.0 |
4.9 |
13.0 |
15.0 |
99.9 |
|
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|
RELATIVE HUMIDITY (%) |
|
|
|
|
|
|
|
|
|
|
|
|
|
mean at 0900UTC |
90 |
89 |
87 |
82 |
77 |
78 |
80 |
84 |
86 |
89 |
90 |
90 |
85 |
mean at 1500UTC |
83 |
76 |
71 |
65 |
64 |
66 |
67 |
68 |
71 |
76 |
80 |
84 |
73 |
|
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|
|
SUNSHINE (hours) |
|
|
|
|
|
|
|
|
|
|
|
|
|
mean daily duration |
1.60 |
2.31 |
3.18 |
4.64 |
5.32 |
4.80 |
4.24 |
4.16 |
3.58 |
2.67 |
2.03 |
1.41 |
3.33 |
greatest daily duration |
7.2 |
9.2 |
11.7 |
13.6 |
15.2 |
15.6 |
15.2 |
13.8 |
11.3 |
9.7 |
8.1 |
6.7 |
15.6 |
mean no. of days with
no sun |
11 |
7 |
5 |
3 |
2 |
2 |
3 |
2 |
4 |
6 |
9 |
12 |
66 |
|
|
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|
|
RAINFALL (mm) |
|
|
|
|
|
|
|
|
|
|
|
|
|
mean monthly total |
75.9 |
54.0 |
61.3 |
52.5 |
61.7 |
55.2 |
59.1 |
77.6 |
70.6 |
83.5 |
74.1 |
78.6 |
804.2 |
greatest daily total |
28.6 |
35.3 |
25.9 |
30.9 |
26.3 |
27.5 |
39.5 |
42.2 |
25.6 |
40.3 |
25.9 |
47.1 |
47.1 |
mean no. of days with >=
0.2mm |
19 |
15 |
18 |
15 |
17 |
16 |
15 |
17 |
17 |
18 |
18 |
19 |
204 |
mean no. of days with >=
1.0mm |
14 |
11 |
13 |
11 |
13 |
11 |
10 |
13 |
12 |
14 |
13 |
14 |
148 |
mean no. of days with >=
5.0mm |
6 |
4 |
4 |
4 |
5 |
3 |
4 |
5 |
5 |
6 |
5 |
6 |
57 |
|
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|
WIND (knots) |
|
|
|
|
|
|
|
|
|
|
|
|
|
mean monthly speed |
8.0 |
8.1 |
8.1 |
7.0 |
6.7 |
6.1 |
5.8 |
6.0 |
6.6 |
7.2 |
7.1 |
7.9 |
7.0 |
max. gust |
85 |
77 |
62 |
58 |
55 |
49 |
49 |
58 |
81 |
65 |
60 |
69 |
85 |
max. mean 10-minute
speed |
51 |
40 |
36 |
34 |
31 |
28 |
27 |
35 |
39 |
40 |
34 |
43 |
51 |
mean no. of days with
gales |
0.4 |
0.4 |
0.1 |
0.0 |
0.0 |
0.0 |
0.0 |
0.0 |
0.0 |
0.1 |
0.0 |
0.2 |
1.2 |
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|
WEATHER (mean no. of days with..) |
|
|
|
|
|
|
|
|
|
|
|
|
|
snow or sleet |
4.9 |
3.8 |
2.7 |
1.1 |
0.1 |
0.0 |
0.0 |
0.0 |
0.0 |
0.0 |
0.6 |
2.6 |
15.9 |
snow lying at 0900UTC |
3.1 |
1.9 |
0.8 |
0.2 |
0.0 |
0.0 |
0.0 |
0.0 |
0.0 |
0.0 |
0.0 |
0.6 |
6.6 |
hail |
0.6 |
0.9 |
2.6 |
1.8 |
1.1 |
0.3 |
0.0 |
0.2 |
0.2 |
0.2 |
0.5 |
0.3 |
8.7 |
thunder |
0.1 |
0.1 |
0.3 |
0.3 |
0.6 |
1.1 |
1.0 |
0.7 |
0.5 |
0.2 |
0.2 |
0.1 |
5.2 |
fog |
3.2 |
1.8 |
1.7 |
2.4 |
1.2 |
1.4 |
1.9 |
3.2 |
3.3 |
3.6 |
2.8 |
3.4 |
29.9 |
