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$61+ Cheap flights from San Diego (SAN) to Illinois

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 4/10. Fares are subject to change and may not be available on all flights or dates of travel.
SAN — ORD
Feb 25 — Mar 41
Tue 2/25
Tue 3/4
1 adult, Economy
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Cheap flight deals from San Diego to Illinois

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

Most accurate provider

FlightHub
3 stars

Most trusted provider

FlightHub
3 stars

Round-trip from

$144
(Frontier)

One-way from

$61
(Frontier)

Popular in

December

Cheapest in

April

Average price

$387

Good round-trip deal

$387 or less

Good one-way deal

$190 or less
Provider with most accurate pricing for San Diego-Chicago (CHI) flight deals.
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Provider most trusted by Cheapflights users for San Diego-Chicago (CHI) flights.
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From San Diego to Illinois
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One-way flight from San Diego to Illinois
Search Deals
Highest demand for flights based on searches. 6% potential increase in price ($27 potential increase over avg. RT price).
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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 San Diego to Illinois.
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Price to beat on a one-way flight from San Diego to Illinois.
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Find flight deals from San Diego to Illinois

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

This Frontier 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 Frontier is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 4/1610:10 amSAN - ORD
1 stop12h 53mFrontier
Sun 4/206:45 amORD - SAN
1 stop6h 44mFrontier
Deal found 2/19$144
This Kiwi.com deal was found by Cheapflights users on 2/18. 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.
Thu 4/37:39 pmSAN - ORD
1 stop27h 03mMultiple Airlines
Sat 4/52:34 pmORD - SAN
1 stop11h 17mMultiple Airlines
Deal found 2/18$145
This Mytrip deal was found by Cheapflights users on 2/18. 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 4/13:29 pmSAN - ORD
2 stops20h 10mSpirit Airlines
Sat 4/52:34 pmORD - SAN
1 stop11h 17mSpirit Airlines
Deal found 2/18$146
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.
Sat 4/59:46 pmSAN - MDW
1 stop5h 47mFrontier
Thu 4/106:45 amMDW - SAN
1 stop6h 44mFrontier
Deal found 2/20$148
This American Airlines 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 American Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 3/186:30 amSAN - STL
1 stop8h 11mAmerican Airlines
Tue 3/255:37 pmSTL - SAN
1 stop6h 34mAmerican Airlines
Deal found 2/19$188
This CheapOair deal was found by Cheapflights users on 2/18. 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 3/38:08 pmSAN - STL
1 stop19h 28mFrontier
Wed 3/56:43 pmSTL - SAN
1 stop26h 34mFrontier
Deal found 2/18$200
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 3/610:12 amSAN - PIA
1 stop23h 30mMultiple Airlines
Mon 3/1012:32 pmPIA - SAN
1 stop13h 02mMultiple Airlines
Deal found 2/20$224
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 4/38:36 amSAN - RFD
1 stop10h 15mMultiple Airlines
Sun 4/69:41 pmRFD - SAN
1 stop20h 54mMultiple Airlines
Deal found 2/20$240
This Booking.com 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 Booking.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 3/206:20 pmSAN - STL
1 stop15h 14mMultiple Airlines
Mon 3/246:55 pmSTL - SAN
1 stop26h 22mMultiple Airlines
Deal found 2/19$255
This Hawaiian Airlines 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 Hawaiian Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 9/2511:30 amSAN - STL
1 stop10h 26mHawaiian Airlines
Sun 9/287:00 amSTL - SAN
1 stop9h 17mHawaiian Airlines
Deal found 2/19$276
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.
Wed 3/126:20 amSAN - STL
1 stop8h 32mDelta
Tue 3/187:40 amSTL - SAN
1 stop6h 45mDelta
Deal found 2/20$277
This United Airlines 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 United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sun 4/207:00 amSAN - STL
1 stop6h 47mUnited Airlines
Tue 4/294:45 pmSTL - SAN
2 stops9h 14mUnited Airlines
Deal found 2/19$282

Find flights from San Diego to Illinois within your budget

Customize your flight search to find flights from San Diego to Illinois 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

San Diego

Fly to

Illinois

Route

Depart

Return

Price

San DiegoChicago

SAN - ORD

SANORD

San Diego

Wed 4/16

10:10 am-1:03 am

1 stop12h 53m

Chicago O'Hare Intl

Sun 4/20

6:45 am-11:29 am

1 stop6h 44m

$144

San DiegoChicago

SAN - ORD

SANORD

San Diego

Thu 4/3

7:39 pm-12:42 am

1 stop27h 03m

Chicago O'Hare Intl

Sat 4/5

2:34 pm-11:51 pm

1 stop11h 17m

$145

San DiegoChicago

SAN - ORD

SANORD

San Diego

Tue 4/1

3:29 pm-1:39 pm

2 stops20h 10m

Chicago O'Hare Intl

Sat 4/5

2:34 pm-11:51 pm

1 stop11h 17m

$146

San DiegoChicago

SAN - MDW

SANMDW

San Diego

Sat 4/5

9:46 pm-5:33 am

1 stop5h 47m

Chicago Midway

Thu 4/10

6:45 am-11:29 am

1 stop6h 44m

$148

San DiegoSt. Louis

SAN - STL

SANSTL

San Diego

Tue 3/18

6:30 am-4:41 pm

1 stop8h 11m

Lambert-St Louis

Tue 3/25

5:37 pm-10:11 pm

1 stop6h 34m

$188

San DiegoSt. Louis

SAN - STL

SANSTL

San Diego

Mon 3/3

8:08 pm-5:36 pm

1 stop19h 28m

Lambert-St Louis

Wed 3/5

6:43 pm-7:17 pm

1 stop26h 34m

$200

San DiegoSt. Louis

SAN - STL

SANSTL

San Diego

Thu 4/17

7:39 pm-9:06 am

1 stop11h 27m

Lambert-St Louis

Tue 4/22

6:30 am-1:00 pm

1 stop8h 30m

$224

San DiegoPeoria

SAN - PIA

SANPIA

San Diego

Thu 3/6

10:12 am-11:42 am

1 stop23h 30m

Greater Peoria

Mon 3/10

12:32 pm-11:34 pm

1 stop13h 02m

$224

San DiegoChicago

SAN - RFD

SANRFD

San Diego

Thu 4/3

8:36 am-8:51 pm

1 stop10h 15m

Chicago Greater Rockford

Sun 4/6

9:41 pm-4:35 pm

1 stop20h 54m

$240

San DiegoSt. Louis

SAN - STL

SANSTL

San Diego

Tue 7/8

6:15 am-4:47 pm

1 stop8h 32m

Lambert-St Louis

Tue 7/22

5:40 pm-10:46 pm

1 stop7h 06m

$277

Flights are sorted by cheapest round-trip flights first.

Deals found on 2/19

Showing 1-10 of 52 results
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Best time to book a flight from San Diego to Illinois

Have a flexible travel schedule? Discover the best time to fly to Illinois from San Diego 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 San Diego to Illinois

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

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

Currently, August is the cheapest month in which you can book a flight from San Diego to Illinois (average of $245). Flying from San Diego to Illinois in March is currently the most expensive (average of $321). 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 SAN to IL?

Find hourly flight availability from San Diego to Illinois. 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.

When flying from San Diego to Illinois, the time of day you decide to fly out makes little to no difference towards the overall price you’ll pay on tickets.

Weekly flight availability from San Diego to Illinois

Explore weekly flight availability from San Diego to Illinois. 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 SAN to USIL are scheduled on a Thursday (28 on average). You will have fewer flight options on Saturday, which is when the least amount of flights are scheduled (19 on average).

Rainfall in Illinois by month

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

In terms of precipitation, rainfall in Illinois ranges from 1.7 - 4.9 inches per month. August is typically the wettest month, when rainfall can reach 4.9 in. January is typically the driest time to visit Illinois when rainfall is around 1.7 in.

Temperature in Illinois by month

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

If weather is an important factor for your trip to Illinois, use this chart to help with planning. For those seeking warmer temperatures, July is the ideal time of year to visit, when temperatures reach an average of 73.4 F. Travelers looking to avoid the cold should look outside of January, when temperatures are typically at their lowest (around 23.0 F).

Reviews of airlines servicing Illinois

Get insights into the airlines that provide service to Illinois. 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 Illinois. Reviews last updated February 20, 2025.
To help decide which airline to fly from San Diego to Illinois, see what other customers have to say about Southwest, Alaska Airlines and Delta. 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

Anonymous,Feb 2025

MCO - STL

Cancelled at last minute, SWA unable to assist in formulating alternate plans. Wound up renting a car and driving 13 hours to beat bad weather forecast at home. Not SWA’s fault that there was significant bad weather across the country.

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

Anonymous,Feb 2025

MCO - STL

Cancelled at last minute, SWA unable to assist in formulating alternate plans. Wound up renting a car and driving 13 hours to beat bad weather forecast at home. Not SWA’s fault that there was significant bad weather across the country.

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

Anonymous,Feb 2025

MCO - STL

Cancelled at last minute, SWA unable to assist in formulating alternate plans. Wound up renting a car and driving 13 hours to beat bad weather forecast at home. Not SWA’s fault that there was significant bad weather across the country.

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

Anonymous,Feb 2025

MCO - STL

Cancelled at last minute, SWA unable to assist in formulating alternate plans. Wound up renting a car and driving 13 hours to beat bad weather forecast at home. Not SWA’s fault that there was significant bad weather across the country.

United Airlines
7.4
Good
8,765 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

Anonymous,Feb 2025

MCO - STL

Cancelled at last minute, SWA unable to assist in formulating alternate plans. Wound up renting a car and driving 13 hours to beat bad weather forecast at home. Not SWA’s fault that there was significant bad weather across the country.

Allegiant Air
7.3
Good
765 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

Anonymous,Feb 2025

MCO - STL

Cancelled at last minute, SWA unable to assist in formulating alternate plans. Wound up renting a car and driving 13 hours to beat bad weather forecast at home. Not SWA’s fault that there was significant bad weather across the country.

Related info for your journey

Find useful and relevant information for your journey from San Diego to Illinois. 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 from for flights from San Diego to Illinois?

    Located just 2.6 mi from the city center, San Diego (SAN) is the airport most travelers will use when flying to Illinois from San Diego.

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

    One-way options have recently been found by users for as low as $61 on Frontier. Other airlines that offer cheap prices include Spirit Airlines from $73 and Alaska Airlines from $138 one-way.

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

    While some choose either San Diego - Chicago Midway or San Diego - Lambert-St Louis, San Diego - Chicago O'Hare Intl is the most popular route from San Diego to Illinois.

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

    The top 3 most reliable airlines when flying from San Diego to Illinois are Qatar Airways (87%), Emirates (87%) and SWISS (87%).

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

    While on average a flight from San Diego to Illinois is generally $960, our data shows the cheapest flight currently is $138. When looking at the most popular route, (San Diego - Chicago O'Hare Intl), you can expect to pay $95 for that flight.

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

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

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

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

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

    Yes. Cheapflights offers flight deals from San Diego to Illinois 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 San Diego to Illinois?

    Currently, August is the cheapest month in which you can book a flight from San Diego to Illinois (average of $245). Flying from San Diego to Illinois in March is currently the most expensive (average of $321). 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.

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Alternative routes for San Diego to Illinois

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

Discover the top 7 airlines that operate flights from San Diego to Illinois. 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
FrontierCheapest$91Average$203FlexibilityNo cancel feeOn-time62%
Spirit AirlinesCheapest$94Average$198FlexibilityNo cancel feeOn-time65%
American AirlinesCheapest$217Average$469FlexibilityNo cancel feeOn-time71%
United AirlinesCheapest$241Average$503FlexibilityNo cancel feeOn-time69%
DeltaCheapest$258Average$378FlexibilityNo cancel feeOn-timeN/A
SouthwestCheapest$332Average$475FlexibilityNo cancel feeOn-time63%
Alaska AirlinesCheapest$391Average$770FlexibilityNo cancel feeOn-time75%
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