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
85.1
76
84
78
87
87
February
88.6
98
83
83
90
86
March
91.7
87
87
91
98
97
April
95.1
93
92
95
97
99
May
97.2
99
94
99
100
June
96.0
89
96
99
98
July
96.9
92
98
95
98
August
96.9
93
96
97
97
September
96.6
96
91
99
98
October
95.5
94
98
91
98
November
93.7
98
93
99
97
December
86.9
78
81
91
93
Average
93.4
88.7
90.5
91.9
95.7
95.9
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
-2.5
-1
1
-5
-2
0
February
0.8
3
1
0
-2
0
March
4.8
7
4
6
7
7
April
12.2
12
16
12
14
11
May
19.5
20
21
20
19
June
24.1
23
23
27
25
July
26.8
27
27
24
29
August
25.8
24
27
27
25
September
21.4
22
20
22
20
October
15.4
16
16
16
14
November
6.7
6
9
7
11
December
1.6
4
3
3
2
Average
12.2
5.4
13.3
13.6
13.6
13.8
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
-10.4
-7
-5
-17
-9
-8
February
-9.0
-6
-10
-11
-12
-9
March
-5.7
-2
-3
-4
-4
-2
April
2.0
2
3
2
3
0
May
7.7
6
8
8
7
June
12.9
13
13
15
13
July
16.4
17
16
15
18
August
15.2
14
16
17
15
September
11.2
12
11
12
9
October
5.8
8
3
8
5
November
-2.3
-2
1
-1
1
December
-6.0
-2
-4
-6
-4
Average
2.6
-4.8
4.2
3.0
3.9
3.8
Average lowest temperature per day
The minimum temperature is typically observed just before sunrise.
Precipitation (%)
Month
Average
2024
2023
2022
2021
2020
January
13.9
21
14
18
8
11
February
13.6
3
20
19
10
17
March
12.3
12
19
12
6
10
April
13.8
20
12
11
16
8
May
8.8
7
7
6
3
June
10.1
11
20
6
5
July
6.9
11
6
11
5
August
6.5
12
7
7
9
September
6.2
3
8
6
7
October
11.2
12
2
14
15
November
11.9
6
12
10
10
December
13.2
13
23
8
11
Average
10.8
14.2
11.5
11.0
8.7
8.6
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
6.1
5
6
7
5
5
February
7.4
8
8
9
7
7
March
8.0
8
8
8
9
8
April
7.7
8
7
8
7
9
May
7.0
8
7
6
8
June
6.4
6
7
7
6
July
5.5
5
5
6
6
August
5.4
5
5
5
5
September
5.7
4
6
6
7
October
6.2
5
6
5
7
November
6.2
6
6
5
7
December
5.7
5
6
6
7
Average
6.5
7.2
6.1
6.6
6.2
6.7
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
006°
352°
006°
347°
055°
February
070°
131°
180°
085°
172°
March
355°
358°
242°
181°
122°
April
074°
130°
324°
003°
350°
May
035°
105°
060°
059°
June
045°
139°
173°
139°
July
135°
153°
096°
122°
August
142°
077°
135°
145°
September
088°
002°
152°
135°
October
149°
138°
095°
157°
November
198°
192°
194°
172°
December
357°
355°
288°
225°
Prevailing wind direction
Average wind direction, weighed by wind speed. Only observations between sunrise and sunset are taken into account.