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
87.7
79
68
91
94
96
February
85.0
75
82
83
86
88
March
85.6
90
81
88
90
77
April
91.6
96
91
93
89
96
May
88.2
84
88
91
91
June
96.7
92
98
99
100
July
93.7
81
98
94
98
August
96.5
96
98
96
100
September
94.1
92
95
99
99
October
90.6
83
96
94
92
November
91.2
87
93
94
98
December
88.2
90
64
97
96
Average
90.5
85.8
85.6
91.4
93.6
94.1
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
3.5
2
0
6
6
6
February
4.2
10
3
5
-3
6
March
10.3
12
7
11
11
11
April
15.7
17
16
16
16
16
May
20.1
23
20
20
20
June
28.2
26
29
30
30
July
31.7
30
33
33
33
August
30.8
31
33
33
34
September
26.7
27
29
28
26
October
16.1
17
18
18
16
November
10.8
12
8
14
14
December
5.5
8
0
8
8
Average
16.1
9.9
16.8
17.8
17.9
18.1
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
-11.3
-13
-12
-11
-8
-9
February
-11.4
-6
-10
-11
-14
-9
March
-6.7
-5
-6
-7
-4
-4
April
-2.5
1
-3
-1
-2
-4
May
5.0
7
4
5
6
June
11.2
11
11
13
12
July
14.6
13
15
16
15
August
12.9
13
14
13
13
September
8.3
9
8
9
6
October
-1.0
0
0
1
-3
November
-6.1
-6
-9
-3
-6
December
-10.5
-7
-12
-8
-10
Average
-1.9
-6.1
0.9
0.4
1.3
0.6
Average lowest temperature per day
The minimum temperature is typically observed just before sunrise.
Precipitation (%)
Month
Average
2024
2023
2022
2021
2020
January
7.9
12
26
8
3
2
February
10.7
15
12
15
10
10
March
7.5
6
14
8
8
5
April
8.3
11
11
7
11
6
May
6.8
6
11
2
5
June
1.8
3
1
1
2
July
1.0
3
1
1
1
August
1.0
1
0
1
0
September
1.8
4
2
1
2
October
4.5
8
1
4
4
November
4.5
9
5
0
1
December
9.2
8
27
5
3
Average
5.7
10.8
8.1
6.4
3.7
3.3
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
10.0
9
8
13
11
11
February
11.0
11
10
13
10
12
March
11.6
11
12
13
11
13
April
12.6
13
12
16
12
12
May
10.4
10
11
11
11
June
9.1
9
9
9
10
July
8.2
7
8
9
8
August
8.7
9
8
9
9
September
9.2
9
9
9
10
October
10.7
10
10
11
11
November
10.5
10
12
12
9
December
11.1
11
13
11
11
Average
10.3
11.0
9.6
11.2
10.3
10.4
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
318°
319°
296°
298°
281°
February
286°
299°
303°
256°
304°
March
298°
290°
320°
291°
279°
April
309°
317°
300°
324°
315°
May
163°
271°
123°
154°
June
137°
225°
135°
275°
July
115°
144°
128°
144°
August
270°
121°
179°
141°
September
310°
160°
285°
293°
October
318°
308°
301°
290°
November
297°
302°
285°
259°
December
298°
306°
254°
297°
Prevailing wind direction
Average wind direction, weighed by wind speed. Only observations between sunrise and sunset are taken into account.