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
81.5
65
85
78
93
78
February
89.1
87
83
88
91
88
March
93.1
97
91
95
94
91
April
96.0
91
93
95
98
May
98.5
100
96
98
100
June
99.8
100
100
100
100
July
97.9
95
99
100
100
August
97.8
96
100
97
93
September
95.3
90
98
90
97
October
91.5
84
93
98
90
November
80.3
82
74
93
78
December
85.2
85
81
89
81
Average
92.7
84.1
91.4
93.1
95.4
93.0
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
-11.6
-14
-5
-10
-7
-18
February
-9.3
-7
-7
-3
-14
-6
March
-1.1
3
-3
1
-2
-2
April
6.2
5
4
6
7
May
14.7
16
12
12
16
June
19.4
20
21
21
17
July
21.6
25
21
22
19
August
19.4
22
20
19
17
September
13.7
13
15
12
14
October
5.3
5
8
5
4
November
-6.9
-1
-5
-7
-8
December
-8.2
-4
-11
-14
-6
Average
4.3
-6.0
7.3
6.7
4.3
4.4
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
-17.0
-19
-10
-17
-13
-25
February
-18.0
-16
-15
-12
-24
-15
March
-12.4
-8
-13
-8
-13
-14
April
-5.6
-3
-6
-7
-4
May
2.8
3
1
3
4
June
7.5
8
8
8
7
July
10.1
11
10
9
9
August
8.9
10
10
9
8
September
3.9
6
5
4
4
October
-2.3
-2
0
-1
-4
November
-11.3
-6
-10
-14
-15
December
-15.5
-11
-20
-22
-13
Average
-5.1
-15.9
-2.2
-3.3
-5.0
-5.1
Average lowest temperature per day
The minimum temperature is typically observed just before sunrise.
Precipitation (%)
Month
Average
2024
2023
2022
2021
2020
January
48.4
53
30
52
43
66
February
39.6
33
43
38
42
47
March
22.9
14
24
23
32
19
April
12.0
22
17
20
8
May
8.4
4
14
16
10
June
10.6
5
14
6
15
July
10.2
6
16
8
12
August
12.5
9
11
16
20
September
10.1
17
5
17
8
October
18.5
24
27
11
18
November
45.4
31
55
37
61
December
34.9
36
26
52
49
Average
21.0
30.8
17.8
21.8
21.6
23.3
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
7.8
7
9
9
9
5
February
7.3
8
8
9
6
9
March
7.9
10
7
9
8
7
April
7.7
8
7
8
7
May
7.9
9
6
8
7
June
6.5
8
5
7
7
July
6.3
6
7
7
7
August
7.3
7
8
8
7
September
7.7
8
10
7
8
October
8.9
9
9
10
8
November
8.9
10
10
7
9
December
9.1
9
7
7
10
Average
7.7
8.5
7.9
7.9
7.7
7.4
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
171°
167°
170°
169°
160°
February
167°
168°
173°
169°
172°
March
172°
148°
163°
175°
078°
April
158°
159°
145°
162°
May
162°
159°
160°
150°
June
160°
145°
155°
158°
July
160°
156°
152°
159°
August
160°
157°
159°
156°
September
158°
160°
155°
156°
October
162°
163°
162°
166°
November
170°
172°
174°
182°
December
170°
196°
188°
172°
Prevailing wind direction
Average wind direction, weighed by wind speed. Only observations between sunrise and sunset are taken into account.