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
79.6
84
66
91
91
80
February
84.5
83
88
94
77
78
March
88.9
83
84
83
93
97
April
93.3
90
94
94
92
May
96.2
99
94
98
97
June
98.8
98
99
99
100
July
99.6
100
100
100
100
August
99.6
100
100
100
100
September
98.8
99
99
98
99
October
91.6
93
95
91
92
November
92.6
91
89
96
94
December
83.5
85
75
83
84
Average
92.0
83.2
91.6
93.5
93.9
93.4
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
-3.2
-2
-4
-3
-1
-2
February
-1.3
2
-3
-1
-1
-2
March
5.1
6
1
5
6
6
April
11.6
8
12
13
11
May
18.0
19
18
19
19
June
24.4
22
24
27
25
July
28.9
29
29
30
29
August
27.7
28
28
27
30
September
23.7
24
24
24
24
October
13.4
16
14
14
15
November
6.5
8
3
9
8
December
-1.5
-1
-2
2
0
Average
11.8
0.4
12.2
13.1
14.1
13.5
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
-12.4
-11
-11
-15
-11
-10
February
-12.9
-9
-14
-14
-10
-14
March
-7.8
-2
-9
-8
-7
-4
April
-3.8
-4
-3
-3
-2
May
2.1
3
1
2
3
June
5.8
6
6
7
6
July
9.7
10
10
11
8
August
8.4
9
10
8
9
September
4.3
4
5
5
3
October
-3.9
-1
-2
0
-4
November
-6.1
-6
-9
-3
-6
December
-12.9
-11
-13
-9
-12
Average
-3.8
-9.3
-2.0
-3.8
-1.1
-2.1
Average lowest temperature per day
The minimum temperature is typically observed just before sunrise.
Precipitation (%)
Month
Average
2024
2023
2022
2021
2020
January
0.0
0
0
0
0
0
February
0.0
0
0
0
0
0
March
0.0
1
0
0
0
0
April
0.0
0
0
0
0
May
0.0
0
0
0
0
June
0.0
0
0
0
0
July
0.0
0
0
0
0
August
0.0
0
0
0
0
September
0.0
0
0
0
0
October
0.0
0
0
0
0
November
0.0
0
0
0
0
December
0.0
0
0
0
0
Average
0.0
0.0
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
1.5
2
2
1
2
2
February
2.2
2
3
1
3
3
March
2.7
4
3
2
3
2
April
5.0
3
7
5
5
May
5.0
4
6
6
5
June
4.3
4
4
4
5
July
3.9
4
3
4
5
August
4.2
4
4
4
5
September
4.4
4
4
4
5
October
3.8
4
4
3
5
November
2.4
2
3
2
3
December
1.6
1
2
3
1
Average
3.4
1.8
3.2
3.6
3.7
3.9
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
238°
221°
235°
227°
217°
February
220°
214°
240°
248°
237°
March
202°
228°
237°
239°
244°
April
242°
242°
235°
241°
May
253°
241°
223°
242°
June
241°
236°
236°
224°
July
247°
237°
255°
233°
August
238°
214°
235°
247°
September
229°
222°
243°
241°
October
235°
228°
241°
245°
November
239°
207°
245°
242°
December
235°
243°
241°
220°
Prevailing wind direction
Average wind direction, weighed by wind speed. Only observations between sunrise and sunset are taken into account.