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
66.7
51
61
77
73
75
February
80.9
92
85
83
80
87
March
86.1
82
84
80
98
88
April
90.5
92
91
89
98
87
May
92.4
99
91
96
92
June
93.0
83
97
92
97
July
96.1
91
98
96
96
August
95.1
89
93
97
99
September
93.0
92
94
99
94
October
87.3
90
95
79
90
November
86.3
89
78
87
91
December
78.8
67
78
88
91
Average
87.3
79.5
85.9
88.6
91.1
91.1
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
0.1
-1
2
-3
0
2
February
2.4
7
3
1
-2
1
March
7.5
10
6
8
11
8
April
13.7
16
15
12
15
12
May
21.0
22
22
21
19
June
26.5
27
27
27
27
July
28.3
27
28
27
30
August
27.2
26
27
29
28
September
23.5
23
23
24
22
October
15.8
16
16
18
14
November
7.7
9
9
8
12
December
3.5
6
3
5
3
Average
13.9
8.0
15.3
14.7
15.3
14.9
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
-6.5
-4
-2
-10
-4
-3
February
-6.6
-3
-4
-8
-10
-5
March
-2.4
1
-2
-2
0
0
April
3.6
6
4
3
4
3
May
9.8
8
12
8
9
June
15.2
14
15
17
15
July
18.0
17
18
18
19
August
16.8
16
17
18
17
September
13.4
13
13
13
12
October
7.1
8
5
11
5
November
0.4
0
1
0
3
December
-3.6
1
-2
-2
-2
Average
5.0
-1.8
6.3
5.5
6.1
5.9
Average lowest temperature per day
The minimum temperature is typically observed just before sunrise.
Precipitation (%)
Month
Average
2024
2023
2022
2021
2020
January
38.3
52
42
39
27
32
February
25.7
8
19
31
33
26
March
17.8
26
26
27
3
11
April
15.1
16
16
22
7
14
May
9.1
7
11
6
10
June
5.2
6
3
10
2
July
3.0
5
4
4
1
August
4.6
7
7
0
2
September
5.7
7
5
5
7
October
14.7
22
11
16
8
November
19.1
15
31
16
10
December
21.3
23
25
18
16
Average
15.0
25.1
15.1
16.5
10.7
10.5
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
9.3
10
9
10
8
9
February
10.4
9
12
11
9
11
March
10.6
11
10
11
12
10
April
10.6
11
10
11
10
10
May
9.1
8
9
9
10
June
8.6
8
9
8
8
July
7.6
7
8
8
7
August
7.3
8
7
6
7
September
7.8
7
7
9
9
October
9.1
8
9
8
10
November
9.7
9
10
10
11
December
9.5
8
10
10
10
Average
9.2
10.3
8.6
9.4
8.8
9.2
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
235°
245°
242°
269°
236°
February
250°
249°
237°
256°
275°
March
256°
272°
265°
240°
231°
April
253°
243°
227°
258°
269°
May
059°
166°
255°
316°
June
359°
256°
237°
232°
July
259°
257°
267°
255°
August
283°
240°
218°
273°
September
158°
273°
251°
234°
October
245°
234°
210°
238°
November
238°
225°
239°
240°
December
268°
175°
226°
256°
Prevailing wind direction
Average wind direction, weighed by wind speed. Only observations between sunrise and sunset are taken into account.