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
86.1
76
84
87
86
91
February
86.5
85
76
91
89
97
March
94.9
96
92
90
97
96
April
95.0
95
93
100
98
May
97.8
95
98
97
100
June
97.6
93
95
99
99
July
94.8
92
98
91
100
August
89.6
90
97
94
99
September
92.4
91
95
99
84
October
92.4
93
98
91
82
November
83.8
84
68
95
90
December
72.9
65
67
80
80
Average
90.8
85.9
88.1
90.8
93.7
93.7
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
-2.2
-4
-1
-1
0
-2
February
-2.2
1
-1
2
-3
2
March
4.4
6
3
6
5
3
April
9.4
9
7
12
9
May
16.9
21
12
16
16
June
19.5
22
18
23
17
July
23.6
25
25
27
21
August
23.8
24
27
24
22
September
18.1
18
21
18
21
October
10.0
11
16
9
8
November
1.9
4
-3
4
2
December
-4.6
1
-9
-8
0
Average
9.0
1.1
11.2
10.5
10.4
9.9
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
-11.4
-11
-9
-12
-10
-12
February
-13.0
-9
-10
-10
-14
-9
March
-8.4
-7
-11
-4
-5
-10
April
-4.4
-4
-6
-3
-5
May
1.9
4
1
1
2
June
4.7
5
5
6
5
July
6.7
6
8
8
7
August
6.2
7
7
7
5
September
2.6
2
2
3
4
October
-3.9
-2
-1
-2
-2
November
-7.6
-5
-13
-4
-6
December
-12.5
-5
-21
-17
-8
Average
-4.5
-9.0
-2.2
-4.9
-3.4
-3.5
Average lowest temperature per day
The minimum temperature is typically observed just before sunrise.
Precipitation (%)
Month
Average
2024
2023
2022
2021
2020
January
14.1
23
21
10
17
6
February
21.7
21
38
21
19
9
March
12.6
19
18
18
7
13
April
8.5
8
13
2
11
May
9.4
15
15
10
10
June
9.7
17
18
5
9
July
5.2
5
6
0
9
August
5.1
9
4
9
4
September
6.6
11
6
8
3
October
8.9
4
8
10
17
November
13.3
5
37
7
13
December
18.6
19
29
37
7
Average
11.4
20.8
14.0
15.1
9.7
9.1
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
8.1
8
8
7
8
9
February
7.2
6
9
8
7
7
March
7.2
7
6
8
9
8
April
7.7
8
8
8
8
May
6.6
6
8
6
7
June
6.3
6
7
6
7
July
5.2
5
6
5
5
August
5.1
5
5
6
6
September
5.8
6
5
7
5
October
7.0
8
6
8
6
November
7.7
8
7
9
8
December
6.6
8
5
6
8
Average
6.7
7.1
6.8
6.5
6.9
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
122°
132°
134°
140°
137°
February
099°
206°
324°
154°
114°
March
108°
134°
316°
150°
305°
April
144°
174°
305°
338°
May
317°
209°
259°
135°
June
316°
197°
092°
144°
July
308°
343°
350°
017°
August
335°
001°
318°
113°
September
138°
099°
145°
115°
October
132°
157°
141°
068°
November
134°
032°
142°
139°
December
135°
036°
090°
137°
Prevailing wind direction
Average wind direction, weighed by wind speed. Only observations between sunrise and sunset are taken into account.