The Statistical Investigation

I Have investigation Wind Speed. At 10 to 12pm the wind speed went 22km but at 7pm the wind speed dropped down to 9km. I thought that the wind speed will go faster and faster but it went fast then slow. Why did the wind speed go too fast to slow? Why did the wind speed 
go slow.

During the day the wind speed
went up to 22 km per hour. As night comes the wind speed dropped down to 9 km  per hour.


I thought that the 3nd chart is the easiest to ready  
because it tells me that the wind speed went fast to slow.