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
90.9
93
78
91
94
94
February
87.6
85
88
81
89
88
March
88.9
86
90
86
88
88
April
91.9
89
91
90
93
95
May
93.8
95
92
95
97
June
97.6
91
100
99
100
July
98.9
97
100
100
100
August
98.8
99
99
99
100
September
95.3
94
94
99
98
October
92.0
91
96
91
92
November
91.2
94
79
94
99
December
92.4
97
85
91
95
Average
93.0
88.1
92.0
91.6
94.6
95.7
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
1.1
1
-3
3
2
3
February
1.4
6
-1
2
-3
-1
March
7.9
9
3
8
7
9
April
13.3
15
11
12
14
12
May
19.2
21
18
20
21
June
26.7
23
26
31
28
July
32.1
31
33
32
32
August
30.3
29
31
30
32
September
25.4
26
27
27
24
October
14.5
15
17
15
15
November
8.1
9
4
11
11
December
2.8
6
1
6
3
Average
14.3
7.8
14.2
15.5
16.0
15.8
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
-9.9
-11
-9
-8
-8
-6
February
-10.3
-5
-10
-11
-13
-9
March
-5.5
-4
-8
-5
-5
-3
April
-2.3
-1
-2
-4
-2
-3
May
3.5
6
2
3
3
June
8.6
9
8
11
9
July
12.4
12
13
14
12
August
11.1
12
11
10
12
September
7.0
7
8
8
6
October
-1.9
0
1
3
-1
November
-4.4
-2
-7
-1
-3
December
-7.2
-5
-9
-6
-7
Average
0.0
-5.0
0.9
0.3
1.2
0.7
Average lowest temperature per day
The minimum temperature is typically observed just before sunrise.
Precipitation (%)
Month
Average
2024
2023
2022
2021
2020
January
12.0
7
31
11
9
7
February
13.7
13
21
19
10
14
March
9.5
7
7
18
10
9
April
10.1
12
11
12
9
7
May
8.6
10
12
3
7
June
3.2
6
1
4
3
July
1.4
1
2
1
3
August
1.8
2
1
1
1
September
4.4
2
6
4
5
October
8.9
12
4
10
7
November
8.8
7
22
5
6
December
7.9
0
15
11
9
Average
7.6
9.7
9.0
9.6
6.0
6.0
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
14.9
13
14
16
15
16
February
14.9
15
17
16
13
15
March
12.5
13
13
13
11
14
April
11.8
11
14
12
11
11
May
9.6
9
10
10
10
June
9.2
8
10
9
11
July
7.7
8
8
7
9
August
8.2
9
7
9
8
September
10.1
10
9
10
11
October
11.8
9
10
12
13
November
14.4
15
14
14
18
December
15.3
13
16
19
16
Average
11.6
12.8
11.2
11.2
11.3
12.3
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
221°
225°
221°
220°
224°
February
226°
223°
228°
229°
224°
March
239°
233°
232°
240°
229°
April
266°
240°
281°
282°
264°
May
279°
268°
355°
244°
June
256°
239°
249°
238°
July
264°
242°
179°
252°
August
249°
248°
241°
257°
September
227°
247°
231°
249°
October
262°
249°
238°
245°
November
220°
227°
230°
227°
December
224°
230°
223°
219°
Prevailing wind direction
Average wind direction, weighed by wind speed. Only observations between sunrise and sunset are taken into account.