Something doesn't look kosher about those charts. Many of them seem to show far more sun at the beginning and end of the month than at the middle of the month. The overall seems reasonable but the details just don't look right to me.
Am I reading them wrong?
My first message was lost.
Let me introduce myself. I am Xavier the creator of
www.aviador.es.
There's nothing wrong with the charts, except for the fact that they are not well explained.
What you see within each month are the hourly statistics, not daily. If you'd count the number of bars, you'd find 24 and not 30 or 31 (well, that would be for an airport that has a 24h weather observer)
In other words: take a look at the topmost chart, you'll see the hour labels in the horizontal axis. Tilt that chart to the right, and that's what will go to the year statistics at the end of the month.
The reason why you see patterns is that there's more IMC near dusk or dawn than near noon (because of the heating from the sun). Remember that the hours are UTC, and therefore you have to account for the time difference from your airport to GMT.
When I created the chart I thought it made a lot more sense to show the information this way.
BTW, take a look at my other favorite airport statistic: the prevailing winds.
Find an example here:
http://www.aviador.es/Weather/Wind/KBOK-9
(this AD -Brookings- does have dependable IMC...)
