Why is Wed more than flying on Thurs in Nov?

Was looking PE flight prices to NYC on the 1st Nov (Thurs) and it came out as £609. Ideally need to be in NY as early as possible on the 1st, so had a look at the previous day's flights (31st Oct) and was given a price of £709.
So how comes there's a £100 price difference for flying earlier in the week? Would have thought that flying closer to the weekend would have been more popular than mid-week. Due to the month?
So how comes there's a £100 price difference for flying earlier in the week? Would have thought that flying closer to the weekend would have been more popular than mid-week. Due to the month?