Hi guys, I have one question for you. Yesterday, I was researching a flight to visit my friend in Burbank, CA, and the price was perfect. But today, I noticed the price rose $20. I know that isn't very much money, but I'm still a student, and I can't afford much more of this. Do flight prices fluctuate up and down by the day, or do they steadily rise until the actual flight date?

bgammill, welcome to FlyerTalk. In general -- and it's only general -- airfares of the type you're looking at are least expensive 21 or 14 days or more from travel dates and get more expensive closer to departure. Often this happens at the 7-day and 3-day (prior to departure) point. There are many exceptions depending on competition in the specific pair of cities you're looking at.

Fare changes can occur daily or even more than once a day. It's not unusual for $20 or higher fluctuations to come and go. Sometimes lower priced seats will exist on some flights that day and not on others. Flights may be lower on Tuesday - Wednesday and Sat., than on other days. With airfares, it's largely unpredictable.

Up and down. Initial prices are based on a demand forecast. Actual demand can be either side of that. If it's lower than expected, prices go down. If it's higher, they go up. Demand is tracked, and fares are adjusted, daily.

Fares rise near the departure date as lower fare classes sell out or become unavailable because their rules require a minimum advance booking. This lets airlines take advantage of the fact that people who book late must often make the trip at any cost, whereas for those who have more lead time it is typically more of a choice.

Bottom line: you'll see fares go up in general, especially within a month or so of departure. Day-to-day fluctuations can be in either direction.

Also, economic conditions and a wide range of external events can affect demand and therefore prices.

There are sites that claim to be able to forecast prices based on historical trends, but they have had limited success. The best-known, farecast, now redirects to Microsoft's new Bing search engine.

Do you mean that the price for that departure day is lower, or do you mean the day you buy a ticket (tuesday, wednesday, saturday) may determine the price of the ticket?

Frankly both are true.

For many carriers, fares are uploaded three times a day on weekdays and once a day on weekends. Additionally, analysts are constantly tweaking availability. So the timing of fare transmissions and analyst changes affect the fares you see.

Additionally, some fares are only valid on Mon-Thurs, TuWeSa, any day but Sunday, etc, etc. So the day you travel changes the fares you get.

Long story short, if you see a fare you're willing to purchase, you should almost always purchase it.

While anything can happen, these tend to be less popular days to travel so fares tend to be lower. This isn't always true, but you can do your own test by checking fares on the same itinerary, a couple of months out, for a range of adjacent dates. Some booking sites make this easy by showing a fare grid for a range of departure and return dates around the date you request.