Very difficult if its still in drought. Wait till September, scarify and aerate. Use mosskiller if essential, otherwise wait and treat it in spring. If you have bald areas, or areas which are incredibly weedy, dig them out, level the soil off and apply lawn seed. If you do seed, don't put any chemical treatments down at all, including mosskiller.

Does moss grow in dry lawn Bamboo? in the wild it tends to like damp.

I'm not suggesting Oldsaggy (how delightful for a name, conjures up all sorts of images, lol) has moss now - but he/she certainly will do by next Spring. Any lawn suffering from drought this year will have more moss than usual by next year as a consequence.

looks like there will be a lot of moss killer sold next year then. I used to have a lot of it until I crowned the lawn with a couple of inches of sand/compost, still get it around the edges though.

Thankyou all