Rendering in poor weather?

Am I being given correct information that Rendering (outdoors obviously)
should not be done in poor weather conditions? Asking because I don't know so be kind please

 

Rendered a wall once, 6 hours later there was heavy rain,went out in the morning and there was a huge sploge of sloppy sand and cement at the bottom of the wall.
Frost and wind can all take their toll on rendering if you cant get some screening up to protect it

 

drizzle fog cool even light rain in largely sheltered areas with scaffold and sheeting could be ok if they know they’re stuff.
anything heavier and as stated it’s a no go.