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
70.1
58
56
94
71
67
February
83.3
91
87
90
84
92
March
87.8
89
89
89
92
74
April
89.7
89
93
97
88
May
90.3
95
89
97
86
June
92.2
87
97
93
99
July
95.3
93
94
95
96
August
93.8
94
91
95
98
September
90.3
88
91
98
81
October
87.5
88
92
85
92
November
89.8
95
91
98
91
December
81.6
67
79
85
94
Average
87.7
82.8
86.5
91.3
91.8
88.3
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
-2.7
-3
1
-4
-1
1
February
2.0
9
4
0
-6
1
March
8.2
11
7
9
11
9
April
14.2
16
12
16
14
May
21.2
24
22
20
20
June
27.1
27
28
28
28
July
27.7
27
27
27
29
August
26.2
27
26
25
28
September
20.4
24
23
0
22
October
14.3
16
17
5
15
November
7.6
9
10
8
12
December
3.5
5
2
6
3
Average
13.5
7.9
15.5
14.6
11.9
15.1
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
-8.3
-7
-4
-13
-6
-5
February
-7.5
-3
-5
-9
-12
-7
March
-1.0
1
-2
-2
1
0
April
3.7
6
3
5
3
May
10.2
10
12
9
10
June
15.9
14
16
18
16
July
17.0
17
18
18
19
August
15.3
15
17
12
16
September
11.3
14
13
0
12
October
5.2
7
5
2
4
November
-2.9
-1
-1
-2
2
December
-4.2
0
-4
-3
-4
Average
4.2
-1.0
5.9
4.7
3.7
5.5
Average lowest temperature per day
The minimum temperature is typically observed just before sunrise.
Precipitation (%)
Month
Average
2024
2023
2022
2021
2020
January
10.6
16
16
4
10
7
February
8.7
2
11
9
12
8
March
7.3
8
7
13
4
13
April
9.4
12
8
6
11
May
7.3
7
10
6
9
June
4.0
2
4
4
2
July
2.7
4
3
4
4
August
2.7
3
4
2
2
September
4.9
8
4
2
7
October
8.4
10
5
12
7
November
7.0
4
12
5
5
December
7.6
15
9
4
4
Average
6.8
9.6
7.2
7.0
5.3
6.2
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
9.2
9
9
11
7
9
February
10.3
10
10
12
9
11
March
10.8
12
11
10
12
11
April
11.1
12
13
11
11
May
9.4
8
11
10
9
June
8.4
8
9
8
8
July
6.8
6
8
7
6
August
6.6
7
7
6
6
September
7.5
6
7
8
9
October
9.2
9
9
8
9
November
10.2
9
11
11
12
December
9.7
9
10
11
9
Average
9.2
10.6
8.2
9.7
8.8
9.0
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
262°
256°
270°
300°
252°
February
244°
254°
249°
302°
295°
March
245°
253°
266°
183°
218°
April
255°
211°
256°
282°
May
092°
154°
195°
064°
June
033°
237°
226°
199°
July
262°
257°
288°
223°
August
277°
224°
194°
232°
September
151°
274°
231°
233°
October
254°
234°
335°
248°
November
244°
227°
238°
222°
December
230°
195°
225°
265°
Prevailing wind direction
Average wind direction, weighed by wind speed. Only observations between sunrise and sunset are taken into account.