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
73.4
59
69
86
76
75
February
84.2
90
83
81
88
84
March
87.6
91
83
90
94
81
April
93.6
95
94
95
94
May
94.1
97
93
93
92
June
95.0
89
97
97
98
July
95.6
90
92
95
98
August
94.8
90
94
97
96
September
92.8
88
91
98
93
October
90.2
91
98
81
92
November
89.3
93
88
91
90
December
84.6
77
80
79
94
Average
89.2
80.1
87.5
91.0
91.2
91.3
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
1.7
0
4
-1
1
4
February
4.8
9
8
2
-1
3
March
9.9
13
9
11
14
10
April
15.9
19
14
17
15
May
22.4
23
24
21
21
June
27.8
27
29
28
29
July
28.7
29
28
28
31
August
27.3
26
28
29
28
September
24.9
25
24
26
23
October
18.1
18
18
20
16
November
9.6
11
12
9
13
December
5.3
8
4
8
5
Average
15.3
7.3
17.2
16.5
16.6
16.4
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
-5.1
-5
-2
-10
-3
-2
February
-5.9
-2
-2
-7
-9
-5
March
0.1
3
0
1
1
1
April
4.5
4
4
5
3
May
11.3
10
13
10
10
June
16.4
14
16
18
16
July
18.6
18
18
18
20
August
16.7
16
17
18
16
September
13.8
13
13
14
12
October
7.7
8
5
11
6
November
0.5
0
1
0
3
December
-2.0
1
-2
0
-3
Average
5.6
-2.7
6.8
6.0
6.9
6.5
Average lowest temperature per day
The minimum temperature is typically observed just before sunrise.
Precipitation (%)
Month
Average
2024
2023
2022
2021
2020
January
27.2
41
30
17
23
23
February
17.6
9
16
28
16
23
March
17.1
11
24
19
5
17
April
13.3
14
18
11
8
May
10.1
7
14
9
12
June
5.4
7
3
7
1
July
4.5
5
8
5
3
August
3.0
6
1
1
4
September
6.3
6
5
5
5
October
11.7
17
5
13
8
November
13.1
8
17
12
12
December
17.4
24
22
12
15
Average
12.5
20.0
12.8
12.4
9.2
10.0
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
9.9
10
9
10
9
9
February
10.4
9
12
11
10
10
March
11.0
12
11
11
11
10
April
10.7
10
12
10
10
May
9.5
8
10
9
10
June
8.5
8
8
8
9
July
6.7
6
7
7
7
August
6.4
7
6
6
6
September
7.0
6
6
9
7
October
8.7
9
9
8
8
November
9.6
9
10
10
11
December
9.3
8
10
10
10
Average
9.0
10.2
8.6
9.0
8.7
8.8
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
248°
254°
257°
253°
236°
February
241°
241°
249°
284°
268°
March
239°
257°
253°
228°
252°
April
237°
227°
249°
271°
May
059°
184°
250°
305°
June
360°
263°
227°
230°
July
252°
238°
262°
237°
August
251°
244°
212°
271°
September
130°
264°
243°
227°
October
249°
236°
230°
223°
November
241°
230°
238°
239°
December
238°
199°
228°
246°
Prevailing wind direction
Average wind direction, weighed by wind speed. Only observations between sunrise and sunset are taken into account.