VFR requirement depends on the airspace.
Class B: tracked on radar so no clouds separation requirements. Clear of clouds. 3 miles visibility.
Class A: none
Class C, D & E (10,000ft MSL or less): visibility 3SM, 500ft below 1000ft above, 2000ft horizontal
Class E (10,000ft MSL or more): visibility 5SM, 1000ft below, 1000ft above, 1SM horizontal
Class G (1200ft or less):
- Day: visibility 1SM, clear of clouds
- Night: visibility 3SM, 500ft below, 1000ft above, 2000ft horizontal
more 1200ft AGL and less 10,000ft MSL:
- Day: visibility 1SM, 500ft below, 1000ft above, 2000ft horizontal
- Night: visibility 3SM, 500ft below, 1000ft above, 2000ft horizontal
more 1200ft AGL and at or above than 10,000ft MSL:
- visibility 5SM, 1000ft below, 1000ft above, 1SM horizontal
FSBO: Few, Scattered, Broken, Overcast