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
88.2
92
84
85
95
February
92.1
87
91
93
96
March
88.0
90
95
85
82
April
92.4
91
99
88
May
85.6
85
89
85
June
95.2
91
97
100
July
97.3
95
99
98
August
98.8
99
99
100
100
September
96.1
96
93
99
95
October
93.6
96
96
96
94
November
93.4
93
93
96
96
December
93.8
92
96
99
91
Average
91.1
89.4
91.9
94.1
93.5
94.7
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
2.7
2
1
5
5
February
4.3
6
4
3
3
March
7.5
5
6
8
7
April
11.9
13
14
11
May
15.2
17
18
16
June
22.4
20
24
25
July
26.2
26
27
25
August
25.9
26
25
25
29
September
23.2
23
24
24
23
October
14.3
15
15
16
16
November
10.0
11
7
13
12
December
5.6
5
5
9
4
Average
11.8
4.1
13.7
14.9
13.9
15.5
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
-9.8
-10
-9
-8
-7
February
-8.4
-5
-8
-10
-10
March
-4.0
-3
-5
-5
-4
April
-1.6
-2
-1
-2
May
3.6
5
2
4
June
7.9
8
4
10
July
11.4
13
7
14
August
12.9
12
12
21
14
September
8.5
8
9
9
7
October
0.3
1
2
2
0
November
-3.3
-2
-6
-2
-3
December
-6.1
-5
-8
-4
-8
Average
0.7
-6.1
1.3
0.2
1.0
0.9
Average lowest temperature per day
The minimum temperature is typically observed just before sunrise.
Precipitation (%)
Month
Average
2024
2023
2022
2021
2020
January
7.6
3
12
10
5
February
6.1
8
7
6
4
March
7.7
9
3
13
12
April
4.5
8
0
5
May
6.8
9
5
7
June
2.8
5
2
2
July
2.1
2
3
2
August
1.6
1
2
0
2
September
2.3
3
3
1
3
October
3.5
4
2
2
3
November
4.4
9
6
1
2
December
4.7
6
4
1
7
Average
6.1
6.4
5.4
4.4
3.7
3.3
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
7.2
6
8
7
8
February
8.3
8
9
7
7
March
8.4
9
10
9
9
April
9.4
9
12
9
May
9.0
8
11
9
June
7.6
7
9
7
July
7.1
7
7
7
August
7.1
7
8
6
8
September
7.4
7
7
7
7
October
7.5
7
7
8
8
November
8.1
7
9
7
10
December
8.3
7
11
11
8
Average
7.8
7.6
7.6
8.5
8.1
8.0
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
274°
235°
241°
253°
February
230°
223°
208°
236°
March
228°
211°
309°
217°
April
232°
221°
276°
May
207°
202°
160°
June
181°
184°
169°
July
182°
203°
203°
August
165°
181°
047°
308°
September
187°
189°
176°
263°
October
211°
270°
203°
216°
November
225°
197°
252°
214°
December
291°
220°
226°
296°
Prevailing wind direction
Average wind direction, weighed by wind speed. Only observations between sunrise and sunset are taken into account.