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
87.5
81
86
81
90
94
February
85.6
75
81
92
88
93
March
92.8
97
94
87
98
92
April
96.6
100
96
99
99
May
98.0
95
97
100
99
June
97.5
98
92
99
98
July
90.3
87
98
92
93
August
86.6
86
100
90
98
September
89.4
86
95
98
85
October
90.1
96
96
85
79
November
86.5
96
65
90
88
December
80.7
81
75
83
89
Average
90.2
84.8
90.9
91.0
93.1
92.8
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
-4
0
-2
1
-3
February
-3.6
1
-1
1
-4
1
March
4.8
7
4
6
6
3
April
9.9
10
8
12
9
May
17.8
22
14
16
17
June
20.4
23
19
23
18
July
23.7
25
24
27
21
August
23.7
25
26
24
21
September
18.2
19
22
18
19
October
10.1
12
16
9
7
November
2.3
4
-4
4
3
December
-4.9
2
-11
-10
2
Average
9.2
1.2
12.2
10.6
10.4
9.8
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
-8.0
-10
-5
-9
-7
-10
February
-11.5
-7
-8
-7
-12
-6
March
-6.8
-5
-8
-3
-3
-7
April
-1.1
0
-2
-1
-2
May
5.8
8
3
5
5
June
8.7
9
8
11
8
July
11.0
11
12
13
10
August
10.7
11
13
11
10
September
6.4
7
8
7
8
October
0.8
1
4
1
0
November
-4.1
-2
-10
-2
-4
December
-9.5
-2
-18
-16
-4
Average
-1.5
-8.8
2.0
0.6
0.6
0.7
Average lowest temperature per day
The minimum temperature is typically observed just before sunrise.
Precipitation (%)
Month
Average
2024
2023
2022
2021
2020
January
14.5
20
15
15
9
15
February
24.3
22
34
18
20
19
March
11.3
5
11
12
7
9
April
7.7
3
7
8
6
May
7.1
5
10
5
11
June
8.5
7
16
5
12
July
6.7
2
3
1
16
August
6.0
8
5
7
6
September
8.0
6
3
11
7
October
11.7
3
4
11
27
November
10.9
5
20
10
12
December
15.5
19
24
17
5
Average
11.0
15.0
8.8
10.4
8.6
11.7
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
8.2
8
8
7
9
9
February
7.2
6
9
8
7
8
March
7.1
7
6
7
9
7
April
7.2
9
8
6
7
May
6.0
5
7
6
6
June
5.9
6
7
5
6
July
4.6
4
4
4
4
August
4.7
5
4
5
5
September
5.9
6
5
7
6
October
7.3
8
6
8
6
November
8.3
9
7
10
9
December
7.2
10
6
6
7
Average
6.6
7.1
6.7
6.4
6.6
6.5
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°
120°
120°
122°
122°
February
121°
122°
148°
127°
124°
March
128°
116°
110°
123°
159°
April
119°
126°
266°
243°
May
296°
158°
164°
138°
June
288°
104°
113°
114°
July
285°
181°
293°
203°
August
260°
158°
260°
144°
September
124°
135°
135°
116°
October
130°
133°
119°
126°
November
126°
149°
120°
121°
December
120°
130°
118°
120°
Prevailing wind direction
Average wind direction, weighed by wind speed. Only observations between sunrise and sunset are taken into account.