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$55+ Cheap flights from Illinois to San Diego (SAN)

This is the cheapest one-way flight price found by a Cheapflights user in the last 72 hours by searching for a flight departing on 4/23. Fares are subject to change and may not be available on all flights or dates of travel.
ORD — SAN
Feb 25 — Mar 41
Tue 2/25
Tue 3/4
1 adult, Economy
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Cheap flight deals from Illinois to San Diego

Keep the following information in mind while searching for Illinois to San Diego flight deals. Data was last updated February 20, 2025.

Most accurate provider

FlightHub
3 stars

Most trusted provider

FlightHub
3 stars

Round-trip from

$140
(CheapOair)

One-way from

$55
(Frontier)

Popular in

March

Cheapest in

April

Average price

$386

Good round-trip deal

$387 or less

Good one-way deal

$215 or less
Provider with most accurate pricing for Chicago (CHI)-San Diego flight deals.
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Provider most trusted by Cheapflights users for Chicago (CHI)-San Diego flights.
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From Illinois to San Diego
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One-way flight from Illinois to San Diego
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High demand for flights, 0% potential price rise
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Cheapest flight prices on average. 1% potential price decrease ($7 potential savings vs. average RT price).
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Average for round-trip flights in February 2025
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Price to beat on a round-trip flight from Illinois to San Diego.
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Price to beat on a one-way flight from Illinois to San Diego.
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Find flight deals from Illinois to San Diego

Cheapest flights from Illinois to San Diego
Explore the most affordable flight options available from Illinois to San Diego. Find the lowest fares from popular airlines and budget airlines, with prices last updated on February 20, 2025.

This CheapOair deal was found by Cheapflights users on 2/19. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure CheapOair is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 3/106:40 amMDW - SAN
1 stop19h 40mFrontier
Thu 3/139:46 pmSAN - MDW
1 stop5h 45mFrontier
Deal found 2/19$140
This Cheapflightsfares deal was found by Cheapflights users on 2/20. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Cheapflightsfares is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 4/42:34 pmORD - SAN
1 stop11h 17mSpirit Airlines
Mon 4/75:30 pmSAN - ORD
1 stop11h 12mSpirit Airlines
Deal found 2/20$142
This Kiwi.com deal was found by Cheapflights users on 2/20. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sun 3/96:45 amORD - SAN
1 stop7h 03mMultiple Airlines
Tue 3/258:07 pmSAN - ORD
1 stop8h 35mMultiple Airlines
Deal found 2/20$144
This Frontier deal was found by Cheapflights users on 2/20. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Frontier is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 3/46:50 amORD - SAN
1 stop6h 58mFrontier
Sat 3/810:29 amSAN - ORD
1 stop8h 45mFrontier
Deal found 2/20$145
This Mytrip deal was found by Cheapflights users on 2/20. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Mytrip is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 3/46:26 pmSTL - SAN
1 stop26h 52mFrontier
Fri 3/76:25 amSAN - STL
1 stop24h 51mFrontier
Deal found 2/20$183
This American Airlines deal was found by Cheapflights users on 2/20. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure American Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 3/196:32 pmMLI - SAN
1 stop7h 02mAmerican Airlines
Wed 3/266:18 amSAN - MLI
1 stop7h 34mAmerican Airlines
Deal found 2/20$229
This American Airlines deal was found by Cheapflights users on 2/20. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure American Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 4/13:15 pmCMI - SAN
1 stop8h 56mAmerican Airlines
Wed 4/26:30 amSAN - CMI
1 stop6h 15mAmerican Airlines
Deal found 2/20$255
This American Airlines deal was found by Cheapflights users on 2/20. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure American Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 4/145:16 pmPIA - SAN
1 stop8h 12mAmerican Airlines
Sat 4/197:12 amSAN - PIA
1 stop5h 51mAmerican Airlines
Deal found 2/20$259
This Delta deal was found by Cheapflights users on 2/19. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 3/267:40 amSTL - SAN
1 stop6h 45mDelta
Mon 3/315:15 pmSAN - STL
1 stop5h 17mDelta
Deal found 2/19$277
This Expedia deal was found by Cheapflights users on 2/20. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Expedia is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 4/23:11 pmSTL - SAN
2 stops18h 24mMultiple Airlines
Sat 4/59:46 pmSAN - STL
1 stop12h 30mMultiple Airlines
Deal found 2/20$283
This Mytrip deal was found by Cheapflights users on 2/20. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Mytrip is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 4/176:11 pmSTL - SAN
2 stops32h 31mSpirit Airlines
Mon 4/218:14 amSAN - STL
3 stops31h 02mSpirit Airlines
Deal found 2/20$285
This Delta deal was found by Cheapflights users on 2/20. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 4/212:15 pmORD - SAN
1 stop10h 05mDelta
Tue 5/67:10 amSAN - ORD
1 stop9h 00mDelta
Deal found 2/20$291

Find flights from Illinois to San Diego within your budget

Customize your flight search to find flights from Illinois to San Diego that fit within your specific budget. Explore options based on user searches and filter the results based on your desired price range. Find flights that match your budget for a cost-effective journey. Over the last 7 days, Cheapflights users made 2,558,603 searches. Data last updated February 20, 2025.

Fly from

Illinois

Fly to

San Diego

Route

Depart

Return

Price

ChicagoSan Diego

MDW - SAN

MDWSAN

Chicago Midway

Mon 3/10

6:40 am-12:20 am

1 stop19h 40m

San Diego

Thu 3/13

9:46 pm-5:31 am

1 stop5h 45m

$140

ChicagoSan Diego

ORD - SAN

ORDSAN

Chicago O'Hare Intl

Fri 4/4

2:34 pm-11:51 pm

1 stop11h 17m

San Diego

Mon 4/7

5:30 pm-6:42 am

1 stop11h 12m

$142

ChicagoSan Diego

ORD - SAN

ORDSAN

Chicago O'Hare Intl

Sun 3/9

6:45 am-11:48 am

1 stop7h 03m

San Diego

Tue 3/25

8:07 pm-6:42 am

1 stop8h 35m

$144

ChicagoSan Diego

ORD - SAN

ORDSAN

Chicago O'Hare Intl

Tue 3/4

6:50 am-11:48 am

1 stop6h 58m

San Diego

Sat 3/8

10:29 am-9:14 pm

1 stop8h 45m

$145

St. LouisSan Diego

STL - SAN

STLSAN

Lambert-St Louis

Tue 3/4

6:26 pm-7:18 pm

1 stop26h 52m

San Diego

Fri 3/7

6:25 am-9:16 am

1 stop24h 51m

$183

MolineSan Diego

MLI - SAN

MLISAN

Moline Quad-City

Wed 3/19

6:32 pm-11:34 pm

1 stop7h 02m

San Diego

Wed 3/26

6:18 am-3:52 pm

1 stop7h 34m

$229

ChampaignSan Diego

CMI - SAN

CMISAN

Champaign University-Willard

Tue 4/1

3:15 pm-10:11 pm

1 stop8h 56m

San Diego

Wed 4/2

6:30 am-2:45 pm

1 stop6h 15m

$255

PeoriaSan Diego

PIA - SAN

PIASAN

Greater Peoria

Mon 4/14

5:16 pm-11:28 pm

1 stop8h 12m

San Diego

Sat 4/19

7:12 am-3:03 pm

1 stop5h 51m

$259

St. LouisSan Diego

STL - SAN

STLSAN

Lambert-St Louis

Wed 3/26

7:40 am-12:25 pm

1 stop6h 45m

San Diego

Mon 3/31

5:15 pm-12:32 am

1 stop5h 17m

$277

St. LouisSan Diego

STL - SAN

STLSAN

Lambert-St Louis

Wed 4/2

3:11 pm-7:35 am

2 stops18h 24m

San Diego

Sat 4/5

9:46 pm-12:16 pm

1 stop12h 30m

$283

Flights are sorted by cheapest round-trip flights first.

Deals found on 2/20

Showing 1-10 of 59 results
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Best time to book a flight from Illinois to San Diego

Have a flexible travel schedule? Discover the best time to fly to San Diego from Illinois with our price prediction graph.
Estimated round-trip price
Rates are based on past data. Find the cheapest month and day to book your flight based on your travel requirements, then search for cheap deals.

Travel insights for flights from Illinois to San Diego

Get recent, data-driven insights about flights from Illinois to San Diego including ideal travel times, pricing trends, and more.

What is the cheapest month to book a flight from Illinois to San Diego?

Currently, August is the cheapest month in which you can book a flight from Illinois to San Diego (average of $286). Flying from Illinois to San Diego in March is currently the most expensive (average of $366). There are several factors that can impact the price of a flight, so comparing airlines, departure airports and flight times can provide users with more options.

What is the cheapest time of day to fly from IL to SAN?

Find hourly flight availability from Illinois to San Diego. Discover flight options and departure times throughout the day, allowing you to choose a departure time that suits your schedule. Data last updated February 20, 2025.

Regardless of the time of day you decide to fly, the ticket price will remain around the same. Book flights from Illinois to San Diego as you normally would.

Weekly flight availability from Illinois to San Diego

Explore weekly flight availability from Illinois to San Diego. Discover flights operating on different days of the week, giving you the flexibility to choose a travel day that best fits your plans. Compare info to find the most convenient option for your journey. Data last updated February 20, 2025.

The most flights from USIL to SAN are scheduled on a Thursday (30 on average). You will have fewer flight options on Tuesday, which is when the least amount of flights are scheduled (17 on average).

Rainfall in San Diego by month

Plan your trip to San Diego by taking into account the average rainfall totals by month.

In terms of precipitation, rainfall in San Diego ranges from 0.0 - 2.3 inches per month. February is typically the wettest month, when rainfall can reach 2.3 in. July is typically the driest time to visit San Diego when rainfall is around 0.0 in.

Temperature in San Diego by month

Plan your trip to San Diego by taking into account the average temperature totals by month.

If weather is an important factor for your trip to San Diego, use this chart to help with planning. For those seeking warmer temperatures, August is the ideal time of year to visit, when temperatures reach an average of 71.6 F. Travelers looking to avoid the cold should look outside of January, when temperatures are typically at their lowest (around 57.2 F).

Reviews of airlines servicing San Diego

Get insights into the airlines that provide service to San Diego. Read reviews, discover amenities, and learn about the overall travel experience offered by airlines. Use this information to make informed decisions when choosing an airline for your flight to San Diego. Reviews last updated February 20, 2025.
To help decide which airline to fly from Illinois to San Diego, see what other customers have to say about Southwest, Breeze Airways and Alaska Airlines. Users can see the overall rating for each airline as well as how each is rated in terms of entertainment options, comfort, food, crew/service, and boarding process.
Southwest
8.1
Very good
4,411 reviews

Boarding

8.2

Entertainment

7.6

Comfort

8.1

Crew

8.7

Food

7.1

Overall

8.1

Reviews

1 / 20

2.0
Mediocre

Bhoopal,Nov 2024

STL - BOS

Flight was delayed by one hour and 40 minutes. Also baggage was delivered late at Boston. This delay made me miss my connection from Boston to Hyderabad

Southwest
8.1
Very good
4,411 reviews
Southwest
8.1
Very good
4,411 reviews

Boarding

8.2

Entertainment

7.6

Comfort

8.1

Crew

8.7

Food

7.1

Overall

8.1

Reviews

1 / 20

2.0
Mediocre

Bhoopal,Nov 2024

STL - BOS

Flight was delayed by one hour and 40 minutes. Also baggage was delivered late at Boston. This delay made me miss my connection from Boston to Hyderabad

Breeze Airways
8.1
Very good
150 reviews
Southwest
8.1
Very good
4,411 reviews

Boarding

8.2

Entertainment

7.6

Comfort

8.1

Crew

8.7

Food

7.1

Overall

8.1

Reviews

1 / 20

2.0
Mediocre

Bhoopal,Nov 2024

STL - BOS

Flight was delayed by one hour and 40 minutes. Also baggage was delivered late at Boston. This delay made me miss my connection from Boston to Hyderabad

Alaska Airlines
8.0
Very good
9,697 reviews
Southwest
8.1
Very good
4,411 reviews

Boarding

8.2

Entertainment

7.6

Comfort

8.1

Crew

8.7

Food

7.1

Overall

8.1

Reviews

1 / 20

2.0
Mediocre

Bhoopal,Nov 2024

STL - BOS

Flight was delayed by one hour and 40 minutes. Also baggage was delivered late at Boston. This delay made me miss my connection from Boston to Hyderabad

Delta
8.0
Very good
8,219 reviews
Southwest
8.1
Very good
4,411 reviews

Boarding

8.2

Entertainment

7.6

Comfort

8.1

Crew

8.7

Food

7.1

Overall

8.1

Reviews

1 / 20

2.0
Mediocre

Bhoopal,Nov 2024

STL - BOS

Flight was delayed by one hour and 40 minutes. Also baggage was delivered late at Boston. This delay made me miss my connection from Boston to Hyderabad

JetBlue
7.4
Good
3,070 reviews
Southwest
8.1
Very good
4,411 reviews

Boarding

8.2

Entertainment

7.6

Comfort

8.1

Crew

8.7

Food

7.1

Overall

8.1

Reviews

1 / 20

2.0
Mediocre

Bhoopal,Nov 2024

STL - BOS

Flight was delayed by one hour and 40 minutes. Also baggage was delivered late at Boston. This delay made me miss my connection from Boston to Hyderabad

Related info for your journey

Find useful and relevant information for your journey from Illinois to San Diego. Access travel guides, tips, and recommendations to enhance your travel experience. Get information about local attractions, weather, transportation options, and more.

  • What airport do you fly into for flights to San Diego from Illinois?

    Most people fly into San Diego (SAN) if they book a flight to San Diego from Illinois. San Diego is conveniently located just 2.6 mi from San Diego’s city center.

  • What are the cheapest airlines to fly from Illinois to San Diego one-way?

    To fly one-way, consider booking your trip with Frontier, which is currently one of the cheapest options available, starting at $55. Spirit Airlines flights start at $90 while deals on Allegiant Air start at $108 one-way.

  • What are the most popular routes from Illinois to San Diego?

    Most travelers choose Chicago O'Hare Intl - San Diego, Chicago Midway - San Diego or Lambert-St Louis - San Diego when deciding on the best route from Illinois to San Diego.

  • What are the most reliable airlines from Illinois to San Diego?

    Consider Brussels Airlines (83%), United Airlines (79%) or Air Canada (79%) when booking your flight. These represent the most reliable airlines when flying from Illinois to San Diego.

  • What are the cheapest flights from Illinois to San Diego?

    The cheapest flight price from Illinois to San Diego is $163. On average you can expect to pay $762. The most popular route, (Chicago O'Hare Intl - San Diego), can usually be booked for $81.

  • Can I find deals for flights from Illinois to San Diego that include hotel bookings?

    Yes. In addition to deals on Illinois to San Diego flights, Cheapflights offers vacation packages that include both flights and hotel.

  • How can I find direct flights from Illinois to San Diego?

    After entering your origin and destination, apply the non-stop filter on the search result page to find direct flights from Illinois to San Diego.

  • Can I find deals for business class flights from Illinois to San Diego?

    Yes. Cheapflights offers flight deals from Illinois to San Diego by cabin class. In addition to browsing deals, you can also filter by cabin class on the search results page after making a search.

  • What is the cheapest month to book a flight from Illinois to San Diego?

    Currently, August is the cheapest month in which you can book a flight from Illinois to San Diego (average of $286). Flying from Illinois to San Diego in March is currently the most expensive (average of $366). There are several factors that can impact the price of a flight, so comparing airlines, departure airports and flight times can provide users with more options.

See more FAQs

Traveling to a place near Illinois?

Book flights to Illinois if you plan to visit one of these locations
El Cajon
Chula Vista
Lemon Grove
National City
Imperial Beach
La Mesa
Alpine
Poway
Santee
Coronado
Borrego Springs

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Alternative routes for Illinois to San Diego

See prices for flight routes from nearby airports that may be better suited for you.
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Top 7 airlines flying from Illinois to San Diego

Discover the top 7 airlines that operate flights from Illinois to San Diego. Compare their services, reliability, and customer satisfaction ratings to choose the airline that best suits your travel preferences and needs. Over the last 7 days, Cheapflights users made 2,558,603 searches. Data last updated February 20, 2025.
AirlineCheapestAverageFlexibilityOn-time
Spirit AirlinesCheapest$103Average$221FlexibilityNo cancel feeOn-time65%
FrontierCheapest$108Average$188FlexibilityNo cancel feeOn-time62%
DeltaCheapest$144Average$418FlexibilityNo cancel feeOn-timeN/A
American AirlinesCheapest$185Average$451FlexibilityNo cancel feeOn-time71%
SouthwestCheapest$218Average$477FlexibilityNo cancel feeOn-time63%
United AirlinesCheapest$246Average$465FlexibilityNo cancel feeOn-time69%
Alaska AirlinesCheapest$403Average$721FlexibilityNo cancel feeOn-time75%
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