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
96.2
97
93
97
96
97
February
90.5
86
94
94
89
94
March
93.3
95
84
94
98
93
April
93.7
98
94
88
97
94
May
94.4
99
92
78
99
June
96.8
94
96
100
98
July
98.8
100
96
99
99
August
97.1
99
97
92
91
September
95.2
96
96
100
88
October
94.2
90
94
98
94
November
94.9
99
92
99
98
December
94.4
97
88
95
97
Average
94.9
94.0
95.0
93.8
94.4
95.5
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
1.1
1
0
2
2
3
February
-1.5
3
0
1
-4
0
March
5.8
9
1
8
7
5
April
11.4
13
10
9
12
13
May
16.6
19
15
14
17
June
22.5
20
23
29
21
July
29.0
29
30
31
27
August
27.5
27
30
25
28
September
22.2
22
26
25
23
October
12.8
14
16
12
15
November
5.5
8
-1
8
7
December
1.5
5
-3
3
3
Average
12.1
6.5
13.0
13.4
13.2
13.5
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
-8.0
-10
-9
-8
-7
-5
February
-10.4
-5
-10
-11
-13
-8
March
-5.1
-5
-8
-3
-4
-5
April
-2.4
0
-2
-4
-3
0
May
3.1
5
2
2
5
June
7.0
6
6
9
8
July
10.1
9
9
12
9
August
9.9
11
11
10
12
September
6.1
6
7
8
6
October
-1.9
1
1
2
1
November
-4.0
-2
-10
-1
-3
December
-8.9
-5
-9
-6
-7
Average
-1.4
-6.8
0.2
-1.5
0.4
1.0
Average lowest temperature per day
The minimum temperature is typically observed just before sunrise.
Precipitation (%)
Month
Average
2024
2023
2022
2021
2020
January
3.2
3
7
4
5
3
February
9.1
14
7
6
11
7
March
6.6
7
17
7
3
7
April
6.4
7
6
10
3
11
May
3.0
2
10
3
1
June
3.3
5
3
0
6
July
0.9
1
0
2
1
August
1.7
4
2
2
2
September
3.5
4
1
0
2
October
4.8
8
5
3
3
November
5.4
2
13
1
1
December
6.2
5
10
4
5
Average
4.6
7.3
5.4
5.4
3.1
3.8
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
12.2
12
12
14
14
13
February
11.5
11
15
14
10
11
March
10.4
11
9
12
12
9
April
10.8
9
12
11
14
9
May
8.3
9
10
6
10
June
7.7
6
9
10
9
July
6.0
6
6
6
7
August
6.1
7
6
7
5
September
7.8
9
7
8
9
October
9.1
7
8
14
7
November
11.8
13
10
15
16
December
12.4
11
16
18
11
Average
9.5
10.4
9.3
9.8
10.7
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
179°
176°
176°
178°
179°
February
174°
174°
176°
179°
174°
March
178°
172°
189°
182°
191°
April
196°
188°
225°
278°
241°
May
201°
227°
331°
199°
June
284°
193°
207°
187°
July
276°
243°
245°
203°
August
187°
231°
186°
284°
September
188°
225°
203°
230°
October
194°
197°
181°
201°
November
181°
177°
181°
179°
December
176°
175°
177°
177°
Prevailing wind direction
Average wind direction, weighed by wind speed. Only observations between sunrise and sunset are taken into account.