$324 Cheap Flights from Champaign (CMI) to San Diego (SAN)

View $324 flight on Wed, Apr 22, 2026Opens in a new window

Popular airlines from Champaign, IL (CMI-University Of Illinois Urbana-Champaign Williard) to San Diego Intl. Airport (SAN)

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Cheap Flights from Champaign to San Diego (CMI-SAN)

Prices were available within the past 7 days and start at $324 for one-way flights and $388 for round trip, for the period specified. Prices and availability are subject to change. Additional terms apply.

American Airlines
Fri, Feb 6 - Wed, Feb 11
CMI
Champaign
SAN
San Diego
$388 Roundtrip, found 4 hours ago
$388
Roundtrip
found 4 hours ago
Select American Airlines flight, departing Fri, Feb 6 from Champaign to San Diego, returning Wed, Feb 11, priced at $388 found 4 hours ago
American Airlines
Fri, Feb 6 - Wed, Feb 11
CMI
Champaign
SAN
San Diego
$412 Roundtrip, found 4 hours ago
$412
Roundtrip
found 4 hours ago
Select American Airlines flight, departing Fri, Feb 6 from Champaign to San Diego, returning Wed, Feb 11, priced at $412 found 4 hours ago
American Airlines
Fri, Oct 3 - Mon, Oct 6
CMI
Champaign
SAN
San Diego
$436 Roundtrip, found 1 day ago
$436
Roundtrip
found 1 day ago
Select American Airlines flight, departing Fri, Oct 3 from Champaign to San Diego, returning Mon, Oct 6, priced at $436 found 1 day ago
American Airlines
Fri, Feb 6 - Wed, Feb 11
CMI
Champaign
SAN
San Diego
$449 Roundtrip, found 4 hours ago
$449
Roundtrip
found 4 hours ago
Select American Airlines flight, departing Fri, Feb 6 from Champaign to San Diego, returning Wed, Feb 11, priced at $449 found 4 hours ago
American Airlines
Fri, Feb 6 - Wed, Feb 11
CMI
Champaign
SAN
San Diego
$452 Roundtrip, found 4 days ago
$452
Roundtrip
found 4 days ago
Select American Airlines flight, departing Fri, Feb 6 from Champaign to San Diego, returning Wed, Feb 11, priced at $452 found 4 days ago
American Airlines
Mon, Oct 20 - Wed, Oct 29
CMI
Champaign
SAN
San Diego
$458 Roundtrip, found 5 days ago
$458
Roundtrip
found 5 days ago
Select American Airlines flight, departing Mon, Oct 20 from Champaign to San Diego, returning Wed, Oct 29, priced at $458 found 5 days ago
American Airlines
Fri, Feb 6 - Wed, Feb 11
CMI
Champaign
SAN
San Diego
$473 Roundtrip, found 4 hours ago
$473
Roundtrip
found 4 hours ago
Select American Airlines flight, departing Fri, Feb 6 from Champaign to San Diego, returning Wed, Feb 11, priced at $473 found 4 hours ago
American Airlines
Mon, Oct 6 - Tue, Oct 14
CMI
Champaign
SAN
San Diego
$478 Roundtrip, just found
$478
Roundtrip
just found
Select American Airlines flight, departing Mon, Oct 6 from Champaign to San Diego, returning Tue, Oct 14, priced at $478 just found
American Airlines
Fri, Oct 3 - Sun, Oct 5
CMI
Champaign
SAN
San Diego
$484 Roundtrip, found 1 day ago
$484
Roundtrip
found 1 day ago
Select American Airlines flight, departing Fri, Oct 3 from Champaign to San Diego, returning Sun, Oct 5, priced at $484 found 1 day ago
American Airlines
Fri, Oct 17 - Sat, Oct 18
CMI
Champaign
SAN
San Diego
$488 Roundtrip, found 5 days ago
$488
Roundtrip
found 5 days ago
Select American Airlines flight, departing Fri, Oct 17 from Champaign to San Diego, returning Sat, Oct 18, priced at $488 found 5 days ago

Find the cheapest month to fly from Champaign (CMI) to San Diego (SAN)

January is typically the cheapest month to fly

From $220 - $728 per traveler.

Frequently asked questions

How much does a flight from University Of Illinois Urbana-Champaign Williard Airport (CMI) to San Diego Intl. Airport (SAN) cost?
Secure a cheap one-way flight from $324 or cheap return flight from $388 from University Of Illinois Urbana-Champaign Williard Airport (CMI) to San Diego Intl. Airport (SAN) with Expedia. Enter your travel dates and sort by "Price (lowest to highest)" to find our cheapest flight offers on this route.
What is the cheapest month to fly from University Of Illinois Urbana-Champaign Williard Airport (CMI) to San Diego Intl. Airport (SAN)?
Flying in February may help you find better deals, as it's the cheapest month for flights between CMI and SAN. You'll often find the lowest fares during the off-season.
What is the cheapest airline that flies from University Of Illinois Urbana-Champaign Williard Airport (CMI) to San Diego Intl. Airport (SAN)?
Expedia's filter tool lets you easily compare different airlines, departure times and fares all in one place. Customize the search to your preferences, then sort by "Price (lowest to highest)" to find out which carrier offers the cheapest CMI to SAN flight.
How many flights per day from University Of Illinois Urbana-Champaign Williard Airport (CMI) to San Diego Intl. Airport (SAN)?
There are no daily direct flights available from University Of Illinois Urbana-Champaign Williard Airport (CMI) to San Diego Intl. Airport (SAN). But you can opt for flights with layovers. Filter your search results on Expedia to include one or more stops, and you'll be on your way in no time at all.
What day of the week has the most flights from CMI to SAN?
Friday is generally the busiest day for flights, while Tuesday is often the quietest.* Keep in mind that flight schedules can vary based on a range of factors, such as the time of year and carrier.*Busiest/quietest day to travel is based on Expedia flight demand through January to December 2024.
What is the best time to fly from University Of Illinois Urbana-Champaign Williard Airport (CMI) to San Diego Intl. Airport (SAN)?
Select a flight from University Of Illinois Urbana-Champaign Williard Airport (CMI) to San Diego Intl. Airport (SAN) that takes off before 3 PM to reduce the risk of cancellations. Departures after this time have a 22% higher chance of being canceled, on average.**Most reliable time of the day and month to travel recommendation is based on January through August 2024 flight status data sourced from OAG's global flight data platform.
Is it cheaper to buy a plane ticket from University Of Illinois Urbana-Champaign Williard Airport (CMI) to San Diego Intl. Airport (SAN) last-minute?
Waiting until right before your break to book a ticket from CMI to SAN often results in higher prices. Although you may find some last-minute deals, they're not always guaranteed. Keep your travel plans flexible to boost your chances of landing a bargain.
Is it cheaper to book a CMI to SAN flight and hotel package?
You'll typically save money by securing a CMI to SAN flight and hotel package compared to booking separately. In fact, travelers could save hundreds of dollars by bundling with Expedia. And it's simple to manage it all in one place. After selecting your preferred flights and accommodations, consider adding extras such as car rentals, tours and activities.
Can I cancel or change the date of my flight from University Of Illinois Urbana-Champaign Williard Airport (CMI) to San Diego Intl. Airport (SAN)?
If you reserved your CMI to SAN flight in the last 24 hours, you may be able to modify or cancel it without any fees. Depending on the airline and the type of fare you have, additional charges may apply for changes beyond this timeframe. Airline policies and contact information can be found in your itinerary or confirmation email. Or, go to our Customer Service portal if you'd like more information.

Travel information

Travel information

Origin airport
University Of Illinois Urbana-Champaign Williard
Destination airport
San Diego Intl.
Airlines serving
American Airlines
Roundtrip price
$388
Distance
1678 mi

Book with confidence

Book with confidence

Champaign to San Diego Flights

The cheapest times to fly from Champaign to San Diego

On average, Thursday can be the cheapest time to fly, according to data from the Airlines Reporting Corporation (ARC), one of the world's biggest databases for global airline sales. The data reveals that you could save up to 16% by flying on a Thursday—the cheapest day to travel on average—instead of a Sunday—the most expensive. Some of the most affordable flights from Champaign to San Diego are during the month of February. You can find some of the cheapest flights from Champaign to San Diego with Expedia's search tool and vast selection of airlines.

 

The best time to book a flight from Champaign to San Diego

Sunday is one of the best days to book for cheap flights from Champaign to San Diego: Tickets reserved on a Sunday cost between 6% and 13% less than those reserved on a Friday, according to ARC data. The data also suggests booking early can also lead to cheaper airfares. You could save 24% by buying your tickets for domestic flights at least a month in advance and 10% by booking international flights 2 months in advance.

 

How to find cheap round-trip tickets from Champaign to San Diego

Being flexible with your dates and using Expedia's Price Drop Protection and Price Tracking features are some of the best ways of finding a cheap ticket from Champaign to San Diego in 2025. You can also book with separate airlines for your outbound and return journeys, from $324 one-way. Expedia also offers Price Drop Protection, so if the cost of your airfare goes down after booking, you'll receive a credit for the difference*. This is available for a small fee, and is free to One Key Gold and Platinum tier members.

 

Expedia's Price Tracking feature means you can stay on top of airfares without manually checking every day. It sends you automated price alerts for cheap Champaign to San Diego flights and uses historical data to indicate when the best time to book is. Download Expedia's free app to activate this handy tool in a few easy taps.

 

You could also save big by booking one of Expedia's vacation packages. Bundling together your Champaign to San Diego airfare with your accommodations and car rental is often cheaper than booking everything separately. There’s also One Key, Expedia's generous rewards program. Join for free and you could earn One Key cash on most bookings to save on future adventures.

 

*Terms apply.

 

Disclaimer: ARC The statistics are based on average round-trip ticket prices between January and August 2023. The percentages you see are averages.

 

Champaign to San Diego Flights

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Explore a world of travel with Expedia

*Available to One Key members.