Especially if your A/C is working at top efficiency<g>

It still may be a bit low though. It's quite possible to be low,
and not fog in some conditions. Myself, I don't really agree
that it's normal. I live in humid Houston, and mine never does
that. None of our cars do.
If you blow fog, that means your evap coil temp is at or
below freezing. Usually, on a slightly low system, this would
occur at idle mostly. The pressure may drop below the freezing
level, but can rise back up when driving due to the higher rpms.
But... You don't have to rely on my jibber jabber.
The best way to check that is just look at the sight glass
if yours has one.  Most that have glasses will be canister looking
things near the front end usually, and will have a little clear sight
glass
on top. Let the a/c crank up full blast and get stable for a while. The
sight
glass should be clear. If you see bubbles flowing across the glass,
it probably needs a shot.  If there is no sight glass, you kinda
have to go by ear.. Myself, I look at the receiver, etc, and charge
until it has a uniform sweatback. But I also use gauges.  The
sight glass is the best way to check with no gauges. Actually,
I'll take it's word over the pressures I see.. But almost always the
pressures will be normal is the glass is clear.
I had to fix the a/c on the accord I just bought. But it was only a
leaking service valve, and a cap with no O-ring. Pulled a vacuum,
charged it, and about 6 weeks later, it's still working good.  :)
Doesn't seem to be leaking at all. Or if it is, it's really small..
Got really lucky. I was expecting it to leak out in a week..
And yep, mine never blows fog, and I do have a clear sight glass.
Between me, and the guy I work with, we still have about 90 lb's
of freon 12.. :) I just bought another 30 lb jug of 12 the other day..
The price was right, and I couldn't pass it up.  Gotta nuff freon to
keep it pumped up for a good while.. I kept the system using 12, cuz
it cools better than retrofiting it to 134a..
MK