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
74.5
61
69
73
90
76
February
81.8
64
89
89
86
90
March
92.4
92
88
91
96
98
April
93.8
94
90
98
95
May
95.9
88
97
98
94
June
96.3
96
94
97
95
July
97.2
99
97
91
99
August
90.8
85
99
80
100
September
90.7
97
86
95
82
October
94.2
91
97
99
87
November
80.7
74
71
89
89
December
74.3
56
80
75
79
Average
88.0
73.0
86.2
89.5
91.6
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
-1.6
-3
-1
-1
2
2
February
-1.9
2
0
2
-2
4
March
7.1
9
5
9
10
7
April
12.0
13
10
15
13
May
19.4
23
16
19
18
June
23.3
25
22
27
21
July
29.6
31
30
33
27
August
28.6
30
31
27
28
September
21.7
21
25
22
23
October
12.6
14
16
15
11
November
3.8
5
-1
7
5
December
0.1
1
-4
-1
2
Average
12.0
2.8
13.9
13.4
14.6
13.3
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
-8.6
-9
-7
-9
-5
-4
February
-9.3
-4
-8
-8
-10
-5
March
-5.8
-3
-7
-2
-2
-4
April
-1.3
-1
-4
-1
-1
May
5.5
8
3
5
6
June
8.7
9
8
10
9
July
9.8
11
9
12
9
August
9.5
11
10
11
9
September
5.6
7
6
5
5
October
-1.4
1
1
0
-1
November
-4.5
-4
-8
-1
-2
December
-6.0
-4
-10
-8
-5
Average
-1.9
-6.3
1.3
0.2
1.3
1.2
Average lowest temperature per day
The minimum temperature is typically observed just before sunrise.
Precipitation (%)
Month
Average
2024
2023
2022
2021
2020
January
18.6
20
16
12
12
29
February
24.5
29
16
19
25
14
March
11.8
12
15
10
5
11
April
13.6
8
13
4
11
May
9.2
12
8
10
12
June
9.3
5
14
8
13
July
1.6
1
1
1
4
August
3.4
6
1
6
2
September
4.6
6
6
4
3
October
8.5
8
7
3
15
November
16.0
14
22
10
17
December
20.1
19
20
28
8
Average
12.5
20.1
10.2
10.4
8.6
11.3
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
3.1
4
2
3
3
4
February
6.2
5
6
6
7
6
March
6.5
7
6
6
6
10
April
7.2
7
8
8
9
May
6.6
6
7
6
8
June
5.9
6
6
6
6
July
5.4
6
5
5
6
August
5.5
5
5
5
7
September
5.6
5
5
5
7
October
5.4
4
5
6
5
November
4.7
3
5
5
5
December
3.5
2
3
6
3
Average
5.6
5.2
4.9
5.4
5.7
6.2
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
020°
135°
303°
204°
184°
February
120°
119°
072°
095°
200°
March
077°
058°
166°
182°
298°
April
164°
159°
091°
159°
May
113°
176°
165°
175°
June
159°
154°
156°
174°
July
199°
118°
138°
181°
August
151°
196°
207°
183°
September
124°
053°
183°
186°
October
030°
184°
195°
286°
November
178°
022°
187°
188°
December
149°
015°
180°
192°
Prevailing wind direction
Average wind direction, weighed by wind speed. Only observations between sunrise and sunset are taken into account.