Percentage of observations where the VFR minimums for ceiling and visibility are met: visibility of 5 mi or more and a ceiling of 3,000 ft or more. Only observations between sunrise and sunset are taken into account.
Marginal VFR conditions (%)
Month
Average
2024
2023
2022
2021
2020
January
75.5
64
77
92
76
75
February
86.5
96
93
85
92
69
March
89.1
89
86
96
93
84
April
91.7
92
94
94
82
May
92.7
99
90
92
90
June
94.1
92
100
90
96
July
93.2
94
91
94
96
August
94.5
94
91
97
95
September
92.4
94
95
93
91
October
86.7
85
89
79
83
November
90.6
92
94
93
89
December
81.3
80
77
82
93
Average
86.8
83.7
90.5
91.9
89.8
89.3
Marginal VFR conditions or better during daylight period
Percentage of observations where the MVFR minimums for ceiling and visibility are met: visibility of 3⅛ mi or more and a ceiling of 1,000 ft or more. Only observations between sunrise and sunset are taken into account.
Maximum temperatures (°C)
Month
Average
2024
2023
2022
2021
2020
January
2.6
2
5
1
2
5
February
6.0
11
10
4
0
5
March
11.3
15
12
13
14
13
April
16.5
20
15
17
14
May
23.6
26
24
22
20
June
27.8
27
29
27
28
July
29.0
28
30
29
30
August
27.8
27
28
29
27
September
25.3
26
24
26
25
October
18.2
19
17
20
17
November
10.5
13
12
10
14
December
6.4
8
5
10
5
Average
14.4
8.9
18.4
17.3
16.6
17.2
Average highest temperature per day
The maximum temperature is typically observed some hours after noon.
Minimum temperatures (°C)
Month
Average
2024
2023
2022
2021
2020
January
-5.6
-5
-1
-9
-4
-2
February
-4.5
-2
-2
-6
-8
-1
March
0.5
4
-1
1
1
5
April
4.2
4
5
5
2
May
11.5
9
13
9
9
June
14.7
14
16
13
16
July
18.7
18
18
20
19
August
16.5
16
16
18
16
September
12.8
12
12
13
11
October
7.4
8
3
11
6
November
0.8
1
1
-1
3
December
-2.4
1
-2
1
-3
Average
4.4
-1.1
6.6
6.1
5.9
6.7
Average lowest temperature per day
The minimum temperature is typically observed just before sunrise.
Precipitation (%)
Month
Average
2024
2023
2022
2021
2020
January
1.7
12
0
0
0
0
February
0.6
4
0
0
0
0
March
0.8
5
0
0
0
0
April
0.0
0
0
0
0
May
0.0
0
0
0
0
June
0.0
0
0
0
0
July
0.0
0
0
0
0
August
0.0
0
0
0
0
September
0.0
0
0
0
0
October
0.6
4
0
0
0
November
0.7
4
0
0
0
December
2.0
10
0
0
0
Average
0.9
6.7
1.2
Precipitation during daylight period
Percentage of observations with observed rain, drizzle, snow or hail. Only observations between sunrise and sunset are taken into account.
Wind speed (knots)
Month
Average
2024
2023
2022
2021
2020
January
8.4
9
8
9
7
8
February
8.8
10
10
9
7
8
March
9.7
11
11
10
8
8
April
8.9
9
10
8
8
May
7.1
7
9
5
7
June
6.1
7
6
4
7
July
5.5
6
6
5
4
August
5.2
6
5
6
5
September
5.5
5
6
7
6
October
7.4
8
7
7
8
November
8.3
9
9
8
9
December
7.9
8
8
9
8
Average
7.8
10.1
7.5
7.8
6.6
6.8
Average wind speed
Excluding wind gusts. Only observations between sunrise and sunset are taken into account.
Prevailing wind direction
Month
2024
2023
2022
2021
2020
January
234°
248°
261°
237°
231°
February
242°
228°
225°
313°
237°
March
224°
236°
232°
214°
040°
April
225°
212°
245°
268°
May
052°
173°
303°
270°
June
011°
246°
220°
217°
July
239°
246°
298°
201°
August
243°
246°
178°
299°
September
116°
273°
231°
215°
October
241°
242°
208°
216°
November
225°
216°
224°
223°
December
208°
194°
203°
233°
Prevailing wind direction
Average wind direction, weighed by wind speed. Only observations between sunrise and sunset are taken into account.