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
82.5
94
59
100
88
80
February
91.1
91
83
95
97
96
March
92.2
95
71
97
97
98
April
98.6
98
99
100
98
May
99.4
100
99
100
100
June
99.6
100
100
100
100
July
99.8
100
100
100
100
August
99.1
100
100
97
100
September
99.2
100
99
99
100
October
98.7
100
98
98
99
November
96.0
96
91
99
98
December
86.9
95
52
94
83
Average
95.2
93.2
91.5
95.3
97.4
96.3
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
-2.7
4
-6
2
-3
-3
February
2.1
7
-7
3
4
2
March
9.8
11
0
11
11
12
April
16.7
14
17
17
17
May
22.8
23
23
24
24
June
29.5
26
30
32
29
July
34.0
34
34
35
34
August
32.1
32
33
31
34
September
26.9
26
28
27
26
October
16.4
18
18
15
19
November
8.6
8
6
11
8
December
0.9
4
-6
2
-2
Average
15.4
7.1
14.4
17.3
17.1
16.7
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
-12.6
-8
-14
-9
-13
-13
February
-10.5
-4
-19
-9
-8
-10
March
-3.6
-1
-9
-2
-2
-1
April
1.2
-1
1
1
1
May
6.8
7
6
8
8
June
11.9
11
12
14
11
July
16.3
16
17
18
15
August
14.4
15
16
14
15
September
9.2
9
11
9
7
October
1.3
3
3
3
1
November
-4.0
-3
-6
-2
-4
December
-10.4
-8
-14
-8
-13
Average
1.2
-5.7
0.7
2.7
2.7
1.4
Average lowest temperature per day
The minimum temperature is typically observed just before sunrise.
Precipitation (%)
Month
Average
2024
2023
2022
2021
2020
January
8.6
3
21
0
2
5
February
8.0
14
10
5
3
1
March
7.6
9
19
5
4
7
April
3.7
2
4
3
4
May
2.9
2
4
1
2
June
1.9
5
1
2
3
July
1.1
1
2
1
1
August
1.3
3
1
1
1
September
3.4
5
5
6
2
October
3.5
3
5
7
1
November
3.8
5
8
1
3
December
5.5
2
14
6
9
Average
4.6
8.6
6.5
4.1
3.0
3.1
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
2.1
3
2
2
2
2
February
3.4
4
3
3
4
4
March
4.8
7
3
4
6
5
April
6.5
6
8
7
6
May
6.1
6
7
7
6
June
5.9
6
6
5
6
July
4.9
5
5
5
6
August
4.7
5
5
4
5
September
4.7
5
4
4
5
October
4.2
4
3
3
5
November
3.2
3
4
3
3
December
2.3
2
2
3
3
Average
4.5
4.4
4.2
4.4
4.5
4.6
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
142°
069°
025°
089°
104°
February
229°
068°
076°
214°
074°
March
211°
062°
141°
127°
214°
April
329°
234°
066°
201°
May
220°
243°
255°
220°
June
235°
248°
221°
241°
July
256°
245°
249°
239°
August
235°
216°
225°
226°
September
232°
208°
184°
179°
October
186°
152°
145°
214°
November
081°
182°
134°
176°
December
143°
093°
226°
073°
Prevailing wind direction
Average wind direction, weighed by wind speed. Only observations between sunrise and sunset are taken into account.