ICAO Doc 4444 says (relevant bits only):
7.3.1.2.1 Prior to taxiing for take-off, aircraft shall be advised of the following elements of information, in the order listed, with the exception of such elements which it is known the aircraft has already received:
b) the surface wind direction and speed, including significant
variations therefrom;
7.3.1.2.2 Prior to take-off aircraft shall be advised of:
a) any significant changes in the surface wind direction and speed, the air temperature, and the visibility or RVR value(s) given in accordance with 7.3.1.2.1.
Hope this helps....