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
2021
2020
January
94.0
100
90
February
97.7
100
March
97.9
98
April
99.2
100
99
May
99.2
100
100
June
99.9
100
July
99.8
August
100.0
September
99.8
October
97.6
100
November
99.7
100
December
96.1
95
Average
98.4
100.0
96.4
100.0
97.1
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
2021
2020
January
4.2
5
3
February
7.6
7
March
13.6
13
April
18.5
19
18
May
22.1
23
26
June
30.3
27
July
32.0
August
31.3
September
27.1
October
17.3
9
November
11.9
9
December
5.8
7
Average
14.0
5.2
7.3
19.0
10.7
Average highest temperature per day
The maximum temperature is typically observed some hours after noon.
Minimum temperatures (°C)
Month
Average
2024
2023
2021
2020
January
-6.6
-5
-6
February
-4.9
-4
March
0.6
2
April
3.8
4
3
May
6.7
6
11
June
12.8
6
July
15.6
August
13.9
September
11.6
October
2.8
1
November
-2.7
-2
December
-6.9
-5
Average
1.1
-6.7
-4.3
4.5
-1.0
Average lowest temperature per day
The minimum temperature is typically observed just before sunrise.
Precipitation (%)
Month
Average
2024
2023
2021
2020
January
6.1
0
5
February
4.9
1
March
5.1
6
April
0.9
2
0
May
3.2
4
0
June
0.9
6
July
0.8
August
0.7
September
1.2
October
4.4
5
November
1.0
3
December
3.6
4
Average
2.5
3.5
2.7
2.8
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
2021
2020
January
3.6
5
3
February
5.5
5
March
6.6
8
April
8.0
9
7
May
7.5
7
12
June
7.5
6
July
5.7
August
5.7
September
7.6
October
5.8
5
November
4.6
5
December
3.0
4
Average
5.8
4.9
4.1
7.7
5.9
Average wind speed
Excluding wind gusts. Only observations between sunrise and sunset are taken into account.
Prevailing wind direction
Month
2024
2023
2021
2020
January
282°
262°
February
289°
March
213°
April
223°
245°
May
276°
221°
June
259°
July
August
September
October
217°
November
264°
December
261°
Prevailing wind direction
Average wind direction, weighed by wind speed. Only observations between sunrise and sunset are taken into account.