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
67.7
56
58
81
67
75
February
80.8
87
82
75
81
87
March
84.2
82
76
85
98
84
April
88.8
89
87
87
92
88
May
92.5
98
90
94
91
June
92.2
78
97
91
99
July
95.2
88
98
93
97
August
93.2
85
91
96
96
September
90.3
89
91
91
90
October
84.3
85
89
71
92
November
84.2
87
82
85
86
December
76.2
51
88
87
85
Average
86.0
79.3
81.3
88.4
88.2
89.8
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
0.0
-1
2
-3
0
2
February
2.7
7
5
1
-2
1
March
7.3
10
6
7
12
9
April
13.6
16
15
12
15
12
May
20.7
21
22
20
19
June
26.0
25
27
27
27
July
28.0
27
28
27
30
August
26.7
25
27
28
28
September
23.0
22
23
23
22
October
15.8
15
16
18
14
November
7.6
9
10
7
12
December
3.2
6
3
5
3
Average
13.7
7.8
14.9
14.8
15.1
14.8
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
-7.8
-5
-3
-11
-5
-4
February
-6.1
-3
-5
-8
-10
-6
March
-2.1
0
-2
-2
-1
0
April
3.5
6
4
2
4
2
May
9.3
6
11
9
9
June
14.4
9
15
17
15
July
17.9
17
17
18
19
August
16.9
15
18
18
17
September
13.3
14
13
13
12
October
7.2
8
5
11
5
November
0.0
0
1
0
3
December
-3.3
1
-2
-2
-3
Average
4.7
-1.6
5.4
5.2
6.0
5.8
Average lowest temperature per day
The minimum temperature is typically observed just before sunrise.
Precipitation (%)
Month
Average
2024
2023
2022
2021
2020
January
31.9
42
29
27
26
32
February
21.8
11
16
33
21
21
March
18.0
18
25
22
4
12
April
14.6
14
19
16
10
12
May
10.2
8
12
9
13
June
6.5
10
5
9
1
July
4.5
5
4
8
3
August
4.4
10
3
1
4
September
5.8
5
8
8
5
October
13.9
16
11
19
9
November
18.2
12
25
19
16
December
20.9
28
17
14
22
Average
14.1
20.4
14.6
14.2
11.2
11.3
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
8.4
8
7
9
7
9
February
9.4
8
10
10
9
10
March
9.7
10
10
10
10
9
April
9.6
10
9
10
9
10
May
8.1
7
8
7
9
June
7.7
7
8
7
7
July
6.9
6
8
7
7
August
6.8
7
7
6
7
September
6.9
6
7
8
7
October
7.9
8
8
7
8
November
8.5
8
9
8
10
December
8.3
7
8
9
9
Average
8.3
9.3
7.6
8.4
7.9
8.3
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
266°
259°
274°
293°
257°
February
261°
253°
261°
285°
283°
March
273°
290°
268°
257°
262°
April
271°
244°
242°
268°
277°
May
351°
166°
271°
304°
June
022°
272°
246°
267°
July
274°
262°
303°
283°
August
302°
273°
269°
289°
September
203°
285°
258°
251°
October
269°
237°
271°
254°
November
258°
240°
244°
248°
December
261°
244°
238°
266°
Prevailing wind direction
Average wind direction, weighed by wind speed. Only observations between sunrise and sunset are taken into account.