Stansted expects to handle more than four million passengers during the summer peak season, with schools set to break-up at the end of the week.
The forecast came as passenger numbers last month bounced back to near pre-pandemic levels.
Almost 2.6 million passengers used the airport in June, up 11% year-on-year and 98% of the level in June 2019.
The total number of passengers handled in the last 12 months was up by 64% to 26.5 million.
Stansted said 97% of passengers passed through security in 15 minutes or less in the three months to June.
As part of its preparations for the summer, the arrivals hall has been refurbished with new seats, improved food and drink options and a new layout designed to help provide a faster and smoother passenger flow.
Seating capacity in the area has increased by 50% to almost 500 seats and includes integrated tables and USB charging points.
A quiet seating area in the departure lounge has also been upgraded, with 200 seats and a variety of charging points.
The airport announced last week it was submitting a planning application for a terminal extension.
The plans aim to “significantly improve” the experience for passengers and provide capacity for the airport’s growth within its agreed planning consent limits.
Chief operating officer Jonathan Fowler said: “This summer’s getaway is already well underway as we welcomed 2.6 million passengers in June, which represents 98% of pre-covid levels.
“These numbers will continue to increase, and we expect this will be our busiest summer ever, with over 4 million passengers passing through during the school holidays.
“In preparation for the getaway, we have upgraded our arrivals hall and the quiet seating area in the departure lounge in order to ensure that passengers have the best possible experience.
“They can be confident we are all working very hard and doing all we can to ensure their holidays get off to the best possible start when flying from London Stansted.”