Here is great example of understanding Tasmanian weather.
So DSS have winter series.
Races start at 0930 on Sundays.
The reason for the 0930 start is that at that time there is cold drainage down the river valley. (ie NW at 10-15 knots)
By midday this has stopped.
So by midday race is over and you are back in the Clubhouse.
But you have had a race in good breeze and all good.