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
93.5
92
95
95
95
100
February
85.5
90
87
86
86
91
March
88.4
84
86
92
95
85
April
88.9
91
98
85
91
May
91.6
97
98
87
95
June
97.5
96
100
97
95
July
98.6
100
96
100
100
August
98.4
97
100
96
100
September
95.3
93
99
100
95
October
89.7
90
91
98
82
November
90.3
99
89
98
90
December
91.6
99
81
92
89
Average
91.4
88.3
94.1
94.7
94.0
93.1
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
1.3
-1
1
3
3
1
February
-3.9
2
0
2
-7
3
March
4.3
6
-1
8
9
4
April
9.8
10
10
10
9
May
15.0
19
15
14
15
June
21.0
20
21
25
20
July
27.3
27
29
30
26
August
27.1
27
30
25
28
September
21.6
22
24
23
22
October
10.4
11
16
14
7
November
4.8
10
-2
9
6
December
1.2
6
-6
-1
3
Average
9.0
2.1
12.9
12.9
12.9
12.3
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
-8.9
-11
-6
-8
-3
-8
February
-11.2
-6
-8
-9
-15
-6
March
-6.4
-5
-8
-3
-3
-6
April
-1.2
-1
-1
-1
-3
May
4.0
8
3
2
4
June
8.7
9
8
10
8
July
12.6
12
14
15
11
August
12.2
12
14
11
12
September
8.5
9
10
9
8
October
0.8
2
7
3
-2
November
-4.7
1
-9
0
-2
December
-7.5
-1
-14
-11
-4
Average
-1.1
-8.8
2.7
1.4
1.5
1.2
Average lowest temperature per day
The minimum temperature is typically observed just before sunrise.
Precipitation (%)
Month
Average
2024
2023
2022
2021
2020
January
10.9
15
8
11
5
8
February
22.5
17
13
15
27
14
March
13.5
11
19
15
8
15
April
15.1
11
9
18
14
May
12.1
10
7
18
7
June
7.3
6
9
6
11
July
1.9
0
2
3
1
August
3.2
3
1
6
2
September
6.8
10
6
1
4
October
11.3
11
6
5
19
November
11.4
1
20
1
9
December
12.5
1
33
18
10
Average
10.8
13.9
7.7
9.8
9.4
9.2
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
14.5
13
14
15
17
15
February
13.0
12
17
15
11
15
March
11.1
9
8
12
13
13
April
12.0
12
12
12
11
May
9.4
8
12
9
10
June
9.0
8
11
8
10
July
8.5
8
9
8
9
August
8.8
9
9
9
9
September
10.9
10
10
12
12
October
12.3
11
9
13
15
November
15.3
15
14
17
17
December
14.3
16
11
15
14
Average
11.6
11.3
10.7
11.5
11.7
11.9
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
186°
188°
206°
215°
211°
February
188°
209°
219°
234°
229°
March
194°
191°
242°
217°
248°
April
215°
242°
264°
249°
May
166°
250°
258°
235°
June
205°
243°
264°
233°
July
229°
212°
233°
222°
August
222°
232°
251°
228°
September
209°
203°
229°
228°
October
190°
194°
219°
230°
November
201°
188°
223°
219°
December
184°
164°
227°
199°
Prevailing wind direction
Average wind direction, weighed by wind speed. Only observations between sunrise and sunset are taken into account.