Question 1

What is the cheapest month to fly to Illinois?

Accepted Answer

The cheapest month to fly to Illinois from San Diego is in February. Flight prices, which tend to average around $232, are often lower during this time because this is during the off-season. If you aren’t able to travel to Illinois during the month of February, then flying in October is also cheap. Prices for this month can be found on momondo for an average of $237.

Question 2

What is the cheapest airline that flies from San Diego to Illinois?

Accepted Answer

Frontier, Alaska Airlines, and Southwest are the most popular carriers operating from San Diego to Illinois

Question 3

Can stopping save me money on San Diego to Illinois flights?

Accepted Answer

You could potentially save up to 35% on your flight if you consider stops on a San Diego to Illinois flight.

Question 4

What cabin class options are available on San Diego to Illinois flights?

Accepted Answer

There are 4 cabin classes available to choose from on San Diego to Illinois flights. Cabin price and availability will vary by airline so perform a search above to find the right deals for you.

Question 5

What is the cheapest time of day to depart on your flight to Illinois?

Accepted Answer

Our most recent data shows that the best time of day to fly to Illinois is in the afternoon. Flights from San Diego to Illinois during this time can be as low as $258. Flights in the morning are often more expensive with an average ticket price of $427.

Question 6

What is the cheapest San Diego to Illinois flight route?

Accepted Answer

Fly from San Diego to Chicago O'Hare Intl for the best San Diego - Illinois flight prices

Question 7

What is the cheapest day to depart on your flight to Illinois?

Accepted Answer

The cheapest day to depart from San Diego to Illinois is on a Friday when prices can be found for as low as $366. Flights from San Diego to Illinois on a Sunday will generally be more expensive and average around $517. Keep in mind that these prices on both days could fluctuate depending on the season and the demand.

Question 8

How far in advance should I book a flight to Illinois?

Accepted Answer

You are more likely to see cheaper flights to Illinois from San Diego when booking weeks ahead of your departure date. In general, you can expect to find flights to Illinois for around $297 when searching weeks out. However, flight prices might be lower outside of this timeframe. For example, people recently found flights to Illinois from San Diego for as low as $249 on momondo.

Question 9

What airlines fly to Illinois?

Accepted Answer

American Airlines, United Airlines and Alaska Airlines are the top three most popular airlines that fly to Illinois from San Diego according to our data. American Airlines is the first choice among our users, with 51% of people opting to fly with this airline when traveling to Illinois. Keep in mind that there are 9 different airlines that fly to Illinois on a routine basis, so you have a few additional options to choose from.

Question 10

How many flights depart from San Diego to Illinois on average per week?

Accepted Answer

274 flights are operational weekly from San Diego to Illinois as of April 2026. The most popular departure day for this route is Mon, with 19% of flights per week taking off on this day.

Question 11

How many flights depart from San Diego to Illinois on average per day?

Accepted Answer

As of April 2026, 39 flights take off from San Diego and land in Illinois each day. The most common flight departure time for this route is 6:00AM, with 46% of daily flights taking off at noon.

Question 12

When did momondo last update prices for flights from San Diego Airport to Illinois?

Accepted Answer

Prices for flights from San Diego Airport to Illinois refresh daily.

Question 13

How many operators does momondo search for flights from San Diego Airport to Illinois?

Accepted Answer

As of April 2026, there are 9 operators available to choose from for flights from San Diego Airport to Illinois.

Question 14

How old do you have to be to fly from San Diego Airport to Illinois?

Accepted Answer

The minimum age for a child to fly alone is five, but airlines offering an unaccompanied minor (UNMR) service may have their age restrictions, such as regulations concerning flight duration, timing, and layovers. It is recommended that you verify with the airline you are booking with for travel from San Diego Airport to Illinois.

Question 15

What documentation or ID do you need to fly to Illinois?

Accepted Answer

The travel and health documents you'll need for your trip to Illinois may differ based on your itinerary and personal situation. Typically, you should have several documents on hand, such as a national ID card or driver's license and a passport that is valid for six months after your intended arrival at Illinois. It is always advisable to seek advice from your airline or a trusted third party, such as IATA.

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