Good reception during the night, bad during the day

What could be the reason that my signal meter sky rockets during the night time, sometimes so high, that after do a scan I notice my tuner maps some extra channels without skips.

Could it be because nothing is in the way during the night like different obstacles or such?

maybe the winds are calmer at night. they usually are here.

Or some sort of solar interference, although i'd expect that from satellite-only.

The interference may not be natural. I know that my UPSs all cycle every morning at 6:00 AM and 6:15AM, sharp -- with such pin-point accuracy that I could set my watch to it -- presumably because two factories in the local area cause a localized power surge by cycling their own equipment. So perhaps you have something nearby that is causing lots of interference during the day, and then shuts down for the evenings.

yea thats what I was thinking because I get all 4 PBS networks during the night and during the day they all go blank

i have the same problem, only the reverse. our PBS stations go off-air though after 5PM

I wonder how much power lines affect signal reception? During the day when more power is being used vs. night time...less power? Or out here in LA, for radio signal broadcasts, some AM stations definitely power down to less output at around 7:30PM-8:00PM.

Its not the station going off air, just the HD tuner in my LCD can't pick up enough signal. During the night like @ 11-12 it sky rockets.