We alway cut it down shorter than normal, blow out the sprinklers, and put down a good winter fertilizer so come spring you won't have to wait until the fert kicks in, the grass will be nice a green and ready to be mowed.
usually 3 in the Spring. On a wet day we will go 3 1/2...less clippings.
Hot summer 3 1/2
Next week going to 3 and final cuts may alittle shorter.
Winter fertilization to keep it green and to start mowing early in the Spring.
If you live in an area that is wet and cold say Long Island NY then cut it shorter than usual to minimize fungus and disease problems. During the yr I cut at 4 even 5". Then I drop down to 3". I get spot areas of mold in the spring but that goes away once it warms up.
I am down at 1.5 " and never really go above 2.5" in the northwest with all the rain and all you couldn't mow at 3" ever- well, maybe in July! Shorter grass is way less work and your rotary deck won't clog as bad