I must be quite unusual here then as I have found I can't clean below -4 as the coldness of the ground freezes the water in the hose. I don't even bother going out until it's above -4 for this reason.
Cheers, Tom
Pretty much the same here.
I think the lowest i've worked in was touching -5, but that was a quick 1/2 hour commercial job.
Another time I was cleaning a large property with about 90 metres of hose out which was laying in the snow at about -3.
Only lasted about 10 minutes before the water froze in the hose and jets.
A hot water system probably would of prevented the water in the hose freezing though on that occasion.