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
2020
January
70.4
69
69
February
84.9
77
93
March
86.0
79
95
April
93.0
95
May
97.4
95
June
98.7
98
July
96.8
97
August
95.6
99
September
97.5
97
October
95.4
93
November
85.9
86
December
65.9
59
Average
87.0
74.8
81.5
92.6
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
2020
January
9.7
10
9
February
11.6
12
16
March
14.8
15
15
April
19.4
21
May
24.9
24
June
28.8
29
July
33.9
34
August
33.7
35
September
27.5
24
October
23.2
24
November
16.2
15
December
8.7
10
Average
19.0
12.3
17.6
21.9
Average highest temperature per day
The maximum temperature is typically observed some hours after noon.
Minimum temperatures (°C)
Month
Average
2024
2023
2020
January
1.6
3
1
February
0.2
2
-2
March
1.4
2
0
April
3.9
4
May
6.5
7
June
9.0
10
July
11.9
12
August
11.7
13
September
8.3
10
October
3.6
6
November
1.2
4
December
1.8
3
Average
4.4
2.3
4.9
5.0
Average lowest temperature per day
The minimum temperature is typically observed just before sunrise.
Precipitation (%)
Month
Average
2024
2023
2020
January
0.0
0
0
February
0.0
0
0
March
0.0
0
0
April
0.0
0
May
0.0
0
June
0.0
0
July
0.0
0
August
0.0
0
September
0.0
0
October
0.0
0
November
0.0
0
December
0.0
0
Average
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
2020
January
2.0
2
2
February
2.9
2
3
March
2.7
2
3
April
3.4
4
May
3.0
3
June
3.4
4
July
2.6
3
August
2.6
3
September
3.1
3
October
2.3
2
November
1.5
1
December
1.2
1
Average
2.5
2.1
1.5
3.0
Average wind speed
Excluding wind gusts. Only observations between sunrise and sunset are taken into account.
Prevailing wind direction
Month
2024
2023
2020
January
214°
215°
February
217°
225°
March
229°
223°
April
226°
May
231°
June
229°
July
222°
August
236°
September
213°
October
216°
November
205°
December
209°
Prevailing wind direction
Average wind direction, weighed by wind speed. Only observations between sunrise and sunset are taken into account.