I wouldn't normally do this but with the mods forgiveness and for the benefit of the OP ......
METAR EGBB 070620Z 34006KT 0250 R15/0400 FG VV/// 05/05 Q1036=
METAR EGBB 070550Z 34004KT 310V020 0200 R15/0350 FG VV///
05/05 Q1036=
So at 0620UTC/0720 BST general visibility 250 meters, vis measured on the lights, along runway 15 (the "R15", or RVR), 400 metres
30 minutes earlier at 0550UTC/0650 BST, general vis 200m, RVR 350.
So as others have mentioned foggy but CAT 3 in it's various forms and CAT 2 almost certainly OK, depending on aircraft type and runway status..