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
78.3
75
68
89
79
83
February
86.4
82
94
90
88
95
March
87.1
92
84
85
92
83
April
85.7
91
83
80
87
89
May
91.2
96
91
91
94
June
92.4
89
95
89
97
July
93.9
92
97
92
96
August
92.3
91
93
89
96
September
91.4
91
95
96
94
October
91.1
88
96
84
98
November
91.8
95
91
94
92
December
82.1
78
93
76
96
Average
88.7
85.8
88.0
91.2
88.6
92.8
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
-3.1
-2
-1
-5
-2
-1
February
-3.9
2
-1
-4
-5
-2
March
2.0
5
1
1
5
3
April
7.5
11
9
6
9
7
May
14.5
16
15
14
14
June
20.6
22
20
22
21
July
23.9
24
24
24
25
August
22.8
22
24
24
23
September
18.9
20
19
20
17
October
11.9
12
12
15
9
November
4.7
6
6
6
8
December
0.4
4
1
1
1
Average
9.4
3.6
11.1
10.2
11.0
10.6
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
-9.6
-6
-5
-14
-7
-6
February
-10.5
-5
-8
-12
-13
-9
March
-5.5
-3
-4
-5
-3
-3
April
-1.8
2
1
-1
1
-2
May
5.0
5
6
5
5
June
11.1
11
11
13
11
July
14.5
14
14
14
17
August
14.5
14
15
16
15
September
11.7
13
11
11
10
October
5.6
7
4
9
3
November
-1.3
0
0
0
1
December
-5.5
-1
-4
-5
-4
Average
2.2
-3.0
3.9
2.5
3.6
3.4
Average lowest temperature per day
The minimum temperature is typically observed just before sunrise.
Precipitation (%)
Month
Average
2024
2023
2022
2021
2020
January
15.5
17
18
16
8
18
February
10.5
3
9
14
12
4
March
10.2
10
17
14
7
12
April
11.1
7
11
16
10
12
May
6.6
5
6
5
8
June
6.3
6
6
6
7
July
3.4
4
2
6
4
August
3.8
5
5
2
3
September
5.7
4
9
4
8
October
8.6
8
8
1
9
November
9.8
9
10
10
3
December
11.9
8
10
16
6
Average
8.4
8.9
8.1
9.2
6.8
7.7
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
7.7
8
8
9
7
7
February
8.0
8
9
8
7
8
March
8.1
8
8
8
9
8
April
7.8
8
9
8
7
8
May
6.9
6
7
7
7
June
6.2
6
7
6
6
July
6.0
5
6
6
6
August
6.1
6
6
6
6
September
7.0
7
8
7
7
October
8.2
8
8
7
9
November
8.5
8
9
8
10
December
7.8
7
7
8
8
Average
7.3
7.9
7.1
7.5
7.1
7.3
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
305°
311°
302°
319°
297°
February
263°
266°
300°
274°
283°
March
307°
003°
318°
255°
241°
April
074°
205°
161°
349°
340°
May
043°
163°
170°
040°
June
024°
215°
194°
204°
July
240°
238°
340°
238°
August
329°
250°
206°
232°
September
139°
307°
258°
230°
October
324°
243°
357°
283°
November
253°
242°
263°
242°
December
291°
213°
257°
288°
Prevailing wind direction
Average wind direction, weighed by wind speed. Only observations between sunrise and sunset are taken into account.