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
78.5
76
60
92
72
79
February
88.8
96
93
92
91
92
March
90.8
94
87
90
92
88
April
90.4
89
90
96
91
May
95.6
96
94
94
97
June
96.9
96
99
98
98
July
96.6
96
96
97
98
August
95.3
97
93
97
99
September
93.5
94
94
95
94
October
92.1
90
98
94
93
November
90.4
99
83
98
94
December
80.5
75
79
80
86
Average
91.1
88.8
89.9
92.4
92.7
92.9
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
-5.5
-3
-4
-7
-3
-3
February
-3.8
5
-2
-5
-7
-2
March
4.4
7
2
3
9
6
April
11.3
11
9
13
13
May
20.4
22
21
20
19
June
26.6
28
27
29
26
July
27.4
27
27
29
28
August
25.7
27
25
27
27
September
22.4
24
23
24
20
October
13.1
14
15
17
10
November
4.4
7
5
6
8
December
-1.1
4
-2
0
0
Average
11.1
2.8
13.3
12.2
13.6
12.5
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
-13.5
-9
-10
-19
-11
-11
February
-14.9
-6
-12
-17
-17
-13
March
-5.0
-3
-7
-5
-2
-2
April
0.5
1
0
2
0
May
8.7
10
9
8
8
June
14.8
15
15
16
15
July
15.8
14
16
16
17
August
14.8
15
15
16
16
September
11.6
14
11
11
9
October
4.0
6
4
7
1
November
-4.4
-3
-3
-3
-2
December
-9.2
-3
-9
-10
-9
Average
1.2
-6.1
3.3
1.8
2.8
2.3
Average lowest temperature per day
The minimum temperature is typically observed just before sunrise.
Precipitation (%)
Month
Average
2024
2023
2022
2021
2020
January
9.2
3
16
8
7
11
February
10.1
3
12
12
9
6
March
8.4
8
16
9
8
11
April
12.7
15
18
12
10
May
7.3
5
9
8
6
June
4.8
2
4
4
5
July
4.0
3
4
3
4
August
5.0
2
6
6
3
September
5.2
6
3
3
5
October
9.0
10
4
3
10
November
7.5
3
16
2
5
December
12.3
6
15
15
8
Average
7.5
5.0
7.6
8.3
6.4
6.8
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
6.5
6
5
7
5
6
February
7.5
8
7
8
7
7
March
7.9
8
7
7
8
8
April
8.8
10
11
8
9
May
7.5
7
9
7
8
June
7.1
6
9
7
7
July
5.1
5
6
5
4
August
5.5
5
6
6
6
September
6.5
6
6
6
6
October
7.6
7
8
6
8
November
8.2
8
9
9
8
December
6.8
6
7
7
6
Average
7.1
7.5
6.6
7.7
6.6
6.9
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
273°
303°
251°
311°
259°
February
261°
260°
281°
272°
267°
March
307°
344°
327°
200°
253°
April
280°
240°
307°
310°
May
141°
182°
196°
039°
June
099°
238°
241°
177°
July
260°
245°
199°
226°
August
145°
215°
198°
230°
September
141°
209°
225°
244°
October
296°
243°
210°
266°
November
237°
246°
269°
230°
December
205°
151°
236°
249°
Prevailing wind direction
Average wind direction, weighed by wind speed. Only observations between sunrise and sunset are taken into account.