Question : What day in the next four weeks has the best fares?
Answer : Since low prices are preferred, look at Mar 21st. As of Mar 20th, it's showing the cheapest ticket sales at $566. That is 20% below the average price for this route, so you can spend that extra cash on a fun experience in London.
Question : Do prices fluctuate more for this route than others?
Answer : Prices for this trip tend to change much more than other flights from the United States. They can vary anywhere from $557 to $3,233. Prices tend to be lower the further out you book.
Question : Which airline is offering the cheapest flight from ONT to LHR?
Answer : British Airways is the leader in keeping prices down for their passengers over the next three months. Bookings are being made at just $557, which is quite a deal when compared to the more expensive bookings of $3,233.
Question : How long do most people visit London?
Answer : Of course you're not most people, but if you were, you'd stay roughly 10 days.
Question : If your plans are flexible, have you considered changing your departure day?
Answer : Saturday is your lowest-cost day to fly in the month of April. Flexibility is paramount when booking travel plans in order to keep travel costs down.