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
76.1
65
60
95
69
85
February
85.2
89
81
91
90
92
March
88.9
94
86
80
96
82
April
91.0
91
93
96
90
May
90.6
95
94
96
86
June
93.7
86
91
96
98
July
96.5
94
97
97
96
August
95.4
96
95
97
99
September
92.0
95
89
98
89
October
92.2
92
97
88
95
November
90.4
92
84
98
91
December
83.4
77
66
88
93
Average
89.4
83.3
87.7
90.1
92.9
91.4
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
-5
-2
1
February
1.0
8
2
0
-6
0
March
7.0
10
6
7
10
8
April
13.4
15
11
15
13
May
21.0
23
23
20
20
June
26.8
28
27
28
27
July
28.3
28
28
28
29
August
26.7
28
27
29
27
September
23.3
24
22
25
21
October
15.2
16
16
18
13
November
7.1
9
10
8
11
December
2.3
5
1
4
1
Average
13.0
4.9
15.3
14.4
14.8
14.2
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
-9.3
-7
-5
-14
-8
-6
February
-9.5
-4
-7
-10
-15
-9
March
-3.7
-1
-3
-3
-1
0
April
2.7
4
2
5
2
May
9.7
9
12
9
9
June
15.4
14
15
17
15
July
17.7
17
18
17
19
August
16.0
15
17
17
16
September
13.0
15
13
12
11
October
6.0
7
4
9
3
November
-2.7
-1
0
-1
2
December
-5.2
-1
-4
-4
-6
Average
3.5
-4.1
5.3
4.5
5.0
4.7
Average lowest temperature per day
The minimum temperature is typically observed just before sunrise.
Precipitation (%)
Month
Average
2024
2023
2022
2021
2020
January
20.4
20
31
16
17
16
February
13.7
3
22
16
10
10
March
13.5
16
14
27
10
14
April
13.9
19
19
5
9
May
10.2
9
9
10
14
June
6.2
3
10
8
5
July
2.7
5
4
3
1
August
4.2
4
7
4
1
September
7.5
7
7
4
13
October
11.2
16
8
12
10
November
12.8
8
29
11
9
December
15.4
17
40
8
7
Average
10.8
13.3
12.1
14.5
7.9
8.7
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
6.9
7
6
8
7
7
February
7.6
7
8
9
7
8
March
8.5
9
8
8
9
8
April
8.7
9
10
8
9
May
7.3
7
8
7
8
June
6.5
6
7
6
6
July
5.7
5
6
6
6
August
5.7
6
6
6
6
September
6.6
7
7
6
7
October
7.4
7
7
7
8
November
7.6
7
8
8
8
December
6.9
7
7
7
6
Average
7.2
7.8
6.8
7.5
6.8
7.1
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
318°
300°
273°
014°
276°
February
231°
320°
299°
292°
307°
March
335°
055°
338°
168°
212°
April
246°
190°
271°
309°
May
083°
147°
160°
063°
June
048°
223°
232°
158°
July
317°
269°
017°
209°
August
042°
226°
193°
223°
September
142°
293°
296°
236°
October
296°
232°
047°
279°
November
244°
222°
240°
226°
December
149°
155°
198°
288°
Prevailing wind direction
Average wind direction, weighed by wind speed. Only observations between sunrise and sunset are taken into account.