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
80.1
65
86
97
74
68
February
90.1
88
90
98
83
98
March
84.8
90
86
98
85
73
April
82.6
92
23
95
96
93
May
90.4
90
92
90
88
June
97.1
97
97
100
98
July
95.1
94
93
92
96
August
93.4
95
94
97
96
September
93.6
89
99
92
97
October
90.6
89
99
87
95
November
93.4
92
96
98
93
December
89.3
89
77
97
89
Average
89.6
84.7
84.9
95.0
91.1
90.5
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
0.9
-3
-1
5
2
1
February
3.4
10
3
6
-4
6
March
10.4
12
7
12
14
11
April
16.7
17
18
17
17
17
May
22.0
24
22
21
20
June
29.4
28
30
30
30
July
29.6
28
31
29
30
August
28.6
29
30
30
30
September
26.3
27
28
27
25
October
17.1
17
20
19
16
November
10.8
12
9
13
13
December
4.5
6
1
7
6
Average
15.7
8.9
16.5
18.2
17.1
17.0
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
-9.2
-11
-9
-11
-6
-7
February
-9.5
-4
-8
-10
-14
-7
March
-2.0
-3
-5
-4
0
0
April
2.1
3
2
2
2
1
May
9.8
10
11
10
9
June
16.2
15
16
16
18
July
17.8
16
18
18
18
August
16.3
16
16
17
16
September
12.8
12
11
13
10
October
3.5
4
3
5
2
November
-3.3
-3
-5
-1
-1
December
-7.6
-5
-8
-6
-6
Average
3.3
-4.4
4.0
3.6
4.7
4.5
Average lowest temperature per day
The minimum temperature is typically observed just before sunrise.
Precipitation (%)
Month
Average
2024
2023
2022
2021
2020
January
7.7
10
6
2
12
7
February
6.5
3
8
3
14
3
March
6.4
6
2
2
14
7
April
5.7
3
4
4
5
6
May
6.7
2
5
5
12
June
1.9
1
1
1
1
July
2.0
4
2
1
1
August
2.5
3
1
1
1
September
2.4
3
1
2
1
October
5.7
6
3
6
2
November
4.4
6
5
3
5
December
8.0
5
15
1
8
Average
4.9
5.2
3.9
3.1
5.0
4.1
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
8.5
8
7
10
8
9
February
9.1
8
10
11
7
9
March
10.6
10
11
13
11
10
April
11.6
11
13
16
11
11
May
8.8
8
10
9
9
June
7.5
7
1
7
11
July
6.6
6
7
7
7
August
6.7
6
7
7
8
September
8.0
7
8
8
9
October
9.5
10
9
9
9
November
9.3
9
10
9
9
December
9.0
8
11
9
9
Average
8.8
9.5
8.3
9.2
8.5
9.1
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
317°
337°
298°
330°
315°
February
301°
309°
321°
331°
322°
March
350°
339°
346°
146°
253°
April
331°
299°
288°
318°
317°
May
144°
274°
144°
012°
June
166°
025°
181°
169°
July
113°
167°
155°
157°
August
189°
149°
150°
167°
September
174°
156°
187°
260°
October
318°
281°
315°
307°
November
272°
309°
290°
257°
December
314°
303°
323°
324°
Prevailing wind direction
Average wind direction, weighed by wind speed. Only observations between sunrise and sunset are taken into account.