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
77.2
74
71
87
74
65
February
88.4
87
89
89
91
91
March
87.1
90
81
93
83
87
April
86.6
91
84
87
94
May
93.8
96
95
96
94
June
96.3
96
100
100
99
July
96.9
98
95
92
99
August
94.2
96
92
97
95
September
93.6
91
99
95
98
October
92.1
87
100
89
89
November
90.6
99
90
95
95
December
82.6
81
71
86
93
Average
89.6
84.1
90.3
92.5
90.8
92.0
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
-3.0
-3
-4
-4
0
-2
February
-2.9
7
-1
-2
-7
0
March
5.8
8
0
5
11
8
April
11.8
12
9
14
14
May
21.5
25
21
21
19
June
28.9
29
29
31
30
July
29.8
29
30
30
31
August
27.6
30
28
29
29
September
24.7
27
26
26
23
October
14.9
16
18
18
11
November
7.1
11
5
9
11
December
1.4
6
-2
0
6
Average
12.9
3.8
14.9
14.0
15.2
15.0
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
-12.4
-11
-11
-16
-7
-11
February
-12.9
-4
-11
-15
-14
-10
March
-4.2
-4
-9
-4
-1
-2
April
1.0
1
0
2
1
May
9.9
11
10
9
9
June
16.8
17
17
17
18
July
17.9
16
18
18
18
August
16.8
17
16
18
17
September
12.8
13
12
13
11
October
4.4
5
5
7
2
November
-3.6
-2
-3
-1
0
December
-8.6
-4
-10
-9
-6
Average
2.5
-7.8
3.7
2.9
4.3
4.1
Average lowest temperature per day
The minimum temperature is typically observed just before sunrise.
Precipitation (%)
Month
Average
2024
2023
2022
2021
2020
January
8.5
8
13
9
6
11
February
8.2
4
7
7
6
6
March
7.4
10
10
2
10
5
April
8.4
9
15
8
2
May
5.8
3
3
5
9
June
3.1
2
2
4
3
July
3.1
2
4
5
3
August
3.4
5
3
2
1
September
4.1
4
2
4
5
October
6.1
8
4
7
8
November
5.9
4
6
4
1
December
8.4
9
22
10
1
Average
6.2
7.5
6.1
5.3
5.6
4.5
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
8.3
8
7
10
8
9
February
8.7
8
9
11
8
9
March
9.2
10
9
11
10
9
April
10.3
10
14
11
10
May
8.3
8
9
9
9
June
7.4
6
9
7
10
July
6.0
6
8
6
7
August
4.9
1
6
7
7
September
7.2
7
7
8
8
October
9.3
9
10
8
10
November
9.9
10
11
9
10
December
8.4
7
10
8
9
Average
8.1
8.8
7.4
9.4
8.1
8.5
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
262°
281°
271°
279°
283°
February
264°
265°
285°
267°
274°
March
312°
286°
306°
221°
261°
April
291°
285°
307°
295°
May
123°
240°
246°
322°
June
114°
258°
242°
169°
July
289°
277°
195°
209°
August
147°
266°
185°
205°
September
164°
223°
235°
269°
October
282°
266°
239°
279°
November
260°
277°
279°
249°
December
237°
256°
282°
286°
Prevailing wind direction
Average wind direction, weighed by wind speed. Only observations between sunrise and sunset are taken into account.