On Tue, 08 Jan 2008 11:02:21 -0800, Richard Fangnail wrote:

How do they report wind speed for a past day in MPH, since the wind is
constantly getting faster or slower? Do they average it, or maybe just
give the maximum speed?

It's recorded as a 24-hour mean of speed and direction with the mean of
the speed of all gusts as well as the maximum gust both noted
separately. Hourly and monthly averages are also recorded. This is used
for climatology records. However, a "normal" report like you get from
the TV for current conditions is the instantaneous direction and speed at
the time the observation is taken. It is not an average.

Stef
Former USAF meteorologist