The latest movements at North Weald show no difference from the last few years. So far! Steady at approx 20,000 p.a.
Sundays are always less busy than Saturdays.
Funnily enough Wednesdays are often busier than Sundays.
If, however, you get a nice day lots of people go abroad which may be why the OP saw less activity in the local area north of Southend. I hate to think what it was like at Le Touquet yesterday.