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
74.8
60
59
92
80
73
February
87.3
92
89
94
82
94
March
87.9
93
84
88
91
80
April
92.4
92
92
91
98
92
May
92.5
96
91
93
91
June
94.4
91
95
98
95
July
96.8
95
97
97
98
August
93.6
90
95
97
98
September
93.7
90
97
95
92
October
92.0
91
97
94
95
November
89.5
98
81
99
88
December
85.4
82
65
91
88
Average
89.9
84.4
88.7
91.3
93.3
90.8
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
-2.0
-2
0
-4
-1
-1
February
1.1
10
3
0
-7
1
March
8.2
13
7
8
11
10
April
15.3
17
17
13
17
16
May
22.7
26
23
21
21
June
28.8
30
29
31
29
July
29.5
29
30
30
31
August
28.1
30
28
30
29
September
25.6
28
25
27
23
October
16.4
18
18
19
14
November
8.2
11
9
10
12
December
3.4
7
2
6
2
Average
14.6
9.3
17.2
15.6
16.3
15.7
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
-11.9
-8
-7
-15
-9
-8
February
-10.5
-4
-8
-12
-16
-9
March
-2.3
0
-3
-1
0
1
April
3.2
5
4
2
5
2
May
10.4
11
11
10
10
June
16.5
16
16
18
18
July
18.4
17
19
18
20
August
16.3
16
18
17
17
September
13.3
15
13
13
11
October
5.5
7
4
9
3
November
-2.0
-1
-2
-1
0
December
-6.3
-2
-6
-5
-7
Average
3.7
-2.0
5.6
4.2
5.2
4.9
Average lowest temperature per day
The minimum temperature is typically observed just before sunrise.
Precipitation (%)
Month
Average
2024
2023
2022
2021
2020
January
8.2
11
14
6
4
8
February
7.0
0
9
6
10
4
March
7.5
9
13
8
5
7
April
7.0
10
6
8
2
6
May
4.8
2
5
7
6
June
3.1
2
3
2
6
July
1.5
2
2
2
1
August
2.4
3
2
2
2
September
4.0
3
4
1
9
October
6.3
4
6
9
4
November
6.3
1
22
1
1
December
6.8
7
20
2
6
Average
5.5
8.1
5.2
6.9
3.8
4.9
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
9.5
9
9
11
8
9
February
10.1
11
10
12
9
9
March
10.9
12
11
11
11
10
April
12.1
13
13
14
11
12
May
9.4
10
10
10
10
June
8.3
7
9
8
10
July
7.4
7
8
7
7
August
7.5
8
7
8
8
September
8.5
8
9
8
9
October
9.8
11
9
9
10
November
10.2
9
11
11
11
December
9.3
10
11
10
8
Average
9.6
11.5
9.2
9.9
9.2
9.5
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
298°
289°
282°
336°
279°
February
266°
277°
301°
310°
302°
March
316°
276°
321°
137°
279°
April
320°
259°
244°
279°
296°
May
126°
158°
161°
044°
June
107°
213°
213°
162°
July
285°
214°
212°
187°
August
206°
180°
168°
202°
September
167°
240°
202°
224°
October
286°
253°
016°
291°
November
253°
256°
262°
227°
December
272°
180°
235°
267°
Prevailing wind direction
Average wind direction, weighed by wind speed. Only observations between sunrise and sunset are taken into account.