Wind has changed direction.
Last week or so it was almost all from the east so what little that was going into Heathrow was approaching via Slough. Wind is now SW again so everything is circling in over London.
Flightradar is a good site, there's this one as well which shows up military flights:
Often a few Typhoons, F16s and Lightning II out over the North Sea with a tanker plus the massive C17 and A400M cargo planes have been doing a fair bit in the quieter skies.
Everything commercial in and out of City is suspended so that's certainly helping with keeping the peace over Dulwich.