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
92.4
91
90
92
97
93
February
91.0
94
85
90
82
92
March
93.4
91
91
93
94
91
April
96.6
94
97
98
94
May
98.6
97
97
100
99
June
96.6
88
96
96
100
July
95.5
92
97
97
94
August
95.3
91
95
95
94
September
97.8
99
99
98
100
October
97.7
92
100
98
100
November
96.5
97
100
92
95
December
89.8
82
87
84
94
Average
95.1
91.7
91.8
95.7
95.2
95.5
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
-1.5
-1
2
-2
3
-7
February
1.5
2
1
3
0
0
March
2.8
3
2
5
1
1
April
7.7
5
7
8
8
May
11.7
10
13
12
13
June
15.3
14
17
14
15
July
17.2
17
17
16
18
August
16.5
17
16
16
16
September
13.4
13
13
12
14
October
8.5
8
8
8
7
November
2.9
5
3
-3
2
December
1.3
0
-1
-1
2
Average
7.4
1.2
7.8
8.5
7.1
7.4
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
-7.5
-7
-2
-7
-3
-15
February
-5.5
-4
-6
-2
-5
-6
March
-5.9
-3
-5
-1
-7
-6
April
0.3
-2
0
0
1
May
4.5
4
4
4
5
June
8.0
8
8
8
7
July
10.3
11
11
10
10
August
9.9
11
10
9
12
September
6.7
6
8
5
10
October
2.6
2
3
2
3
November
-3.1
-1
-3
-9
-3
December
-5.5
-7
-7
-7
-3
Average
0.9
-5.4
1.6
2.2
0.5
1.1
Average lowest temperature per day
The minimum temperature is typically observed just before sunrise.
Precipitation (%)
Month
Average
2024
2023
2022
2021
2020
January
13.4
18
11
14
18
9
February
15.1
16
30
14
24
12
March
12.1
15
18
12
9
15
April
9.5
10
14
5
9
May
8.4
13
2
5
7
June
5.0
9
3
4
1
July
8.6
11
10
10
8
August
13.2
16
24
9
18
September
13.0
15
17
14
6
October
13.5
12
11
21
7
November
16.9
23
16
15
15
December
23.8
29
23
24
19
Average
12.0
15.7
15.2
12.2
11.4
9.6
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
5.3
6
4
6
6
5
February
6.4
8
7
6
6
6
March
6.1
6
7
5
6
6
April
5.8
5
6
6
6
May
6.2
6
7
5
6
June
5.8
5
6
7
6
July
5.3
5
5
5
6
August
5.5
5
5
6
5
September
5.2
5
5
6
7
October
5.5
4
6
6
5
November
5.5
7
5
6
6
December
6.0
6
5
6
6
Average
5.8
6.5
5.5
5.7
5.8
5.8
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
057°
061°
061°
053°
045°
February
077°
353°
245°
028°
091°
March
089°
064°
076°
357°
203°
April
220°
120°
187°
239°
May
148°
240°
223°
221°
June
189°
241°
226°
230°
July
227°
234°
228°
228°
August
230°
226°
240°
209°
September
224°
157°
065°
173°
October
070°
056°
147°
064°
November
276°
040°
045°
047°
December
071°
013°
017°
075°
Prevailing wind direction
Average wind direction, weighed by wind speed. Only observations between sunrise and sunset are taken into account.