WMO standards indicate the wind speed will be determined from the average over the 10 minutes preceding the observation.
According to https://library.wmo.int/doc_num.php?explnum_id=3425
"The wind reported should be the mean over the 10 min preceding the observation.
If during this period there has been a marked discontinuity lasting at least 2 min,
the mean values should be assessed over the period after the discontinuity.
A marked discontinuity occurs when there is a wind direction
change of 30° or more with a wind speed of 10 kt (5 m/s) or more,
before or after the change, or a wind speed change of 10 kt (5 m/s) or more.
The averaging period for measuring variations from the mean wind speed (gusts)
should be 3 sec."