How many flights depart from State of Washington to Illinois on average per week?

As of August 2025, 721 flights take off from State of Washington and land in Illinois each week. The most common flight departure day for this route is Sun, with 19% of weekly flights taking off on this day.

How many flights depart from State of Washington to Illinois on average per day?

103 flights are operational daily from State of Washington to Illinois as of August 2025. The most popular departure time for this route is 1:00PM, with 50% of flights per day taking off at noon.

What airlines fly to Illinois?

Delta, Alaska Airlines and American Airlines are the top three most popular airlines that fly to Illinois from State of Washington according to our data. Delta is the first choice among our users, with 28% of people opting to fly with this airline when traveling to Illinois. Keep in mind that there are 8 different airlines that fly to Illinois on a routine basis, so you have a few additional options to choose from.

What is the cheapest airline that flies from Washington to Illinois?

United Airlines, Frontier, and American Airlines are the most popular carriers operating from Washington to Illinois

How long is the flight from State of Washington to Illinois?

The flight from State of Washington to Illinois depends on which airports you’re departing and arriving from and whether or not you have a layover. If you fly from Spokane (a popular airport in State of Washington) to Chicago O'Hare Intl Airport (the most popular airport in Illinois), then the flight time is 3h 35m on average. If you fly from Seattle (another popular airport in State of Washington) to Chicago O'Hare Intl Airport, then the average flight time is 3h 59m.

When did momondo last update prices for flights from Washington to Illinois?

Prices for flights from Washington to Illinois are refreshed on a daily basis.

How many operators does momondo search for flights from Washington to Illinois?

The number of operators available for flights from Washington to Illinois is 8 as of August 2025.

How old do you have to be to fly from Washington to Illinois?

The minimum age a child must be to fly alone is five but airlines that offer an unaccompanied minor (UNMR) service will have their own age restrictions, including rules around flight length, timings, and stopovers. We always recommend checking with the individual airline you are booking with to travel from Washington to Illinois.

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

The required travel and health documents for your Illinois trip may vary depending on your itinerary and personal circumstances. As a general rule, you should carry multiple documents, including a national ID card or driver's license and a passport valid for six months after your intended arrival at Illinois. We recommend that you seek guidance from your airline or a reliable third party such as IATA.

$84 Cheap Flights from Washington to Illinois in 2025

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Find the cheapest flights from Washington to Illinois

Round-trip

One-way

Last minute

Direct

Cheap round-trip flights

11:10 pm - 8:35 amSEA-STL

7h 25m1 stop

9:20 am - 11:40 amSTL-SEA

4h 20mnonstop

$167Southwest

Find Deal

Sat, Sep 20 - Sat, Sep 27

7:00 am - 9:06 amSEA-STL

24h 06m1 stop

7:55 pm - 10:59 pmSTL-SEA

29h 04m1 stop

$173Frontier

Find Deal

Wed, Sep 10 - Tue, Sep 16

5:30 am - 1:44 pmSEA-STL

6h 14m1 stop

10:40 am - 5:39 pmSTL-SEA

8h 59m1 stop

$177Delta

Find Deal

Sat, Sep 20 - Sat, Sep 27

6:00 am - 4:45 pmSEA-STL

8h 45m1 stop

7:00 pm - 11:59 pmSTL-SEA

6h 59m1 stop

$183Delta

Find Deal

Tue, Sep 16 - Fri, Sep 19

11:54 pm - 5:55 amSEA-ORD

4h 01mnonstop

6:00 am - 1:03 pmORD-SEA

9h 03m1 stop

$190United Airlines

Find Deal

Fri, Sep 5 - Tue, Sep 16

12:34 am - 6:42 amSEA-ORD

4h 08mnonstop

7:15 am - 9:49 amORD-SEA

4h 34mnonstop

$192American Airlines

Find Deal

Tue, Oct 7 - Wed, Oct 15

12:17 am - 6:24 amSEA-ORD

4h 07mnonstop

8:20 am - 3:08 pmORD-SEA

8h 48m1 stop

$199Alaska Airlines

Find Deal

Mon, Oct 6 - Wed, Oct 15

1:40 pm - 12:03 amGEG-ORD

8h 23m1 stop

8:00 am - 12:46 pmORD-GEG

6h 46m1 stop

$204Alaska Airlines

Find Deal

Sat, Sep 20 - Tue, Sep 23

8:00 am - 6:25 pmSEA-ORD

8h 25m1 stop

7:10 am - 9:43 amORD-SEA

4h 33mnonstop

$210United Airlines

Find Deal

Wed, Sep 3 - Sat, Sep 13

6:28 am - 6:41 pmSEA-STL

10h 13m1 stop

3:59 pm - 9:23 pmSTL-SEA

7h 24m1 stop

$217American Airlines

Find Deal

Sat, Sep 20 - Sat, Sep 27

Hawaiian Airlines flights from State of Washington to Illinois

Our best Hawaiian Airlines deals on State of Washington to Illinois flight tickets

Hawaiian Airlines

Sep 3

SEA12:59 amSeattle/Tacoma Intl

4h 04m

ORD7:03 amChicago O'Hare Intl

Sep 13

ORD7:00 amChicago O'Hare Intl

9h 26m

1 stop

SEA2:26 pmSeattle/Tacoma Intl

$203

Find similar

Hawaiian Airlines

Sep 3

SEA12:59 amSeattle/Tacoma Intl

4h 04m

ORD7:03 amChicago O'Hare Intl

Sep 13

ORD7:00 amChicago O'Hare Intl

9h 26m

1 stop

SEA2:26 pmSeattle/Tacoma Intl

$204

Find similar

Hawaiian Airlines

Sep 4

SEA3:59 pmSeattle/Tacoma Intl

4h 08m

ORD10:07 pmChicago O'Hare Intl

Sep 13

ORD2:07 pmChicago O'Hare Intl

6h 38m

1 stop

SEA6:45 pmSeattle/Tacoma Intl

$205

Find similar

Spirit Airlines flights from State of Washington to Illinois

Our best Spirit Airlines deals on State of Washington to Illinois flight tickets

Spirit Airlines

Aug 30

PDX7:52 pmPortland

13h 51m

1 stop

ORD11:43 amChicago O'Hare Intl

Sep 5

ORD6:15 amChicago O'Hare Intl

6h 56m

1 stop

PDX11:11 amPortland

$184

Find similar

Spirit Airlines

Oct 2

PDX12:07 pmPortland

7h 29m

1 stop

ORD9:36 pmChicago O'Hare Intl

Oct 7

ORD6:40 amChicago O'Hare Intl

14h 56m

1 stop

PDX7:36 pmPortland

$194

Find similar

Spirit Airlines

Sep 10

PDX12:07 pmPortland

7h 25m

1 stop

ORD9:32 pmChicago O'Hare Intl

Sep 16

ORD7:09 pmChicago O'Hare Intl

18h 02m

2 stops

PDX11:11 amPortland

$195

Find similar

Fly from

Fly to

Route

Depart

Return

Price

SeattleSt. Louis

SEA - STL

SEASTL

Seattle/Tacoma Intl

Sat 9/20

11:10 pm-8:35 am

1 stop7h 25m

Lambert-St Louis

Sat 9/27

9:20 am-11:40 am

Nonstop4h 20m

$167

SeattleSt. Louis

SEA - STL

SEASTL

Seattle/Tacoma Intl

Wed 9/10

7:00 am-9:06 am

1 stop24h 06m

Lambert-St Louis

Tue 9/16

7:55 pm-10:59 pm

1 stop29h 04m

$173

SeattleSt. Louis

SEA - STL

SEASTL

Seattle/Tacoma Intl

Sat 9/20

5:30 am-1:44 pm

1 stop6h 14m

Lambert-St Louis

Sat 9/27

10:40 am-5:39 pm

1 stop8h 59m

$177

SeattleSt. Louis

SEA - STL

SEASTL

Seattle/Tacoma Intl

Tue 9/16

6:00 am-4:45 pm

1 stop8h 45m

Lambert-St Louis

Fri 9/19

7:00 pm-11:59 pm

1 stop6h 59m

$183

SeattleChicago

SEA - ORD

SEAORD

Seattle/Tacoma Intl

Fri 9/5

11:54 pm-5:55 am

Nonstop4h 01m

Chicago O'Hare Intl

Tue 9/16

6:00 am-1:03 pm

1 stop9h 03m

$190

SeattleChicago

SEA - ORD

SEAORD

Seattle/Tacoma Intl

Tue 10/7

12:34 am-6:42 am

Nonstop4h 08m

Chicago O'Hare Intl

Wed 10/15

7:15 am-9:49 am

Nonstop4h 34m

$192

SeattleChicago

SEA - ORD

SEAORD

Seattle/Tacoma Intl

Mon 10/6

12:17 am-6:24 am

Nonstop4h 07m

Chicago O'Hare Intl

Wed 10/15

8:20 am-3:08 pm

1 stop8h 48m

$199

SpokaneChicago

GEG - ORD

GEGORD

Spokane

Sat 9/20

1:40 pm-12:03 am

1 stop8h 23m

Chicago O'Hare Intl

Tue 9/23

8:00 am-12:46 pm

1 stop6h 46m

$204

SeattleChicago

SEA - ORD

SEAORD

Seattle/Tacoma Intl

Wed 9/3

8:00 am-6:25 pm

1 stop8h 25m

Chicago O'Hare Intl

Sat 9/13

7:10 am-9:43 am

Nonstop4h 33m

$210

SeattleSt. Louis

SEA - STL

SEASTL

Seattle/Tacoma Intl

Sat 9/20

6:28 am-6:41 pm

1 stop10h 13m

Lambert-St Louis

Sat 9/27

3:59 pm-9:23 pm

1 stop7h 24m

$217

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How to get the cheapest flight ticket from State of Washington to Illinois

Look no further. We've gone through all the searches for this route on momondo so you have the important information and insights to find the cheapest flight ticket for your trip

Prices

Airlines

Other information

What is the cheapest month to fly to Illinois?

The cheapest month to fly to Illinois from State of Washington is in January. Flight prices, which tend to average around $223, 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 January, then flying in September is also cheap. Prices for this month can be found on momondo for an average of $255.

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

The cheapest day to depart from State of Washington to Illinois is on a Wednesday when prices can be found for as low as $395. Flights from State of Washington to Illinois on a Sunday will generally be more expensive and average around $506. Keep in mind that these prices on both days could fluctuate depending on the season and the demand.

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

Our most recent data shows that the best time of day to fly to Illinois is in the afternoon. Flights from State of Washington to Illinois during this time can be as low as $288. Flights in the morning are often more expensive with an average ticket price of $456.

What is the cheapest Washington to Illinois flight route?

Fly from Spokane to Chicago O'Hare Intl for the best Washington - Illinois flight prices

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

You are more likely to see cheaper flights to Illinois from State of Washington when booking weeks ahead of your departure date. In general, you can expect to find flights to Illinois for around $305 when searching weeks out. However, flight prices might be lower outside of this timeframe. For example, people recently found flights to Illinois from State of Washington for as low as $260 on momondo.

What cabin class options are available on Washington to Illinois flights?

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

Can stopping save me money on State of Washington to Illinois flights?

No. A direct flight is the cheapest option for a flight between State of Washington to Illinois.

Cheap State of Washington to Illinois flight deals and tips

Find info about flight duration, direct flights, and airports for your flight from State of Washington to Illinois

Best Price Found	$160
Fastest flight time	3h 23m
Direct flights	Every day
Airports in Illinois	2 airports

The best one-way flight to Illinois from State of Washington in the past 72 hours is $160. The best round-trip flight deal from State of Washington to Illinois found on momondo in the last 72 hours is $270.

The fastest flight from State of Washington to Illinois takes 3h 23m

Direct flights go from State of Washington to Illinois every day.

There are 2 airports near Illinois: Chicago O'Hare Intl (ORD), Lambert-St Louis (STL)

Search flight deals

When did momondo last update prices for flights from Washington to Illinois?
Prices for flights from Washington to Illinois are refreshed on a daily basis.
How many operators does momondo search for flights from Washington to Illinois?
The number of operators available for flights from Washington to Illinois is 8 as of August 2025.
How old do you have to be to fly from Washington to Illinois?
The minimum age a child must be to fly alone is five but airlines that offer an unaccompanied minor (UNMR) service will have their own age restrictions, including rules around flight length, timings, and stopovers. We always recommend checking with the individual airline you are booking with to travel from Washington to Illinois.
What documentation or ID do you need to fly to Illinois?
The required travel and health documents for your Illinois trip may vary depending on your itinerary and personal circumstances. As a general rule, you should carry multiple documents, including a national ID card or driver's license and a passport valid for six months after your intended arrival at Illinois. We recommend that you seek guidance from your airline or a reliable third party such as IATA.
What is the most popular plane model from State of Washington to Illinois?
momondo data reveals that the most frequently booked plane model on the route from State of Washington to Illinois is Boeing 737-900 Passenger/BBJ3 (winglets), representing 15.90% of all bookings. The subsequent popular models are Boeing 737-800 at 14.88%, Boeing 737 MAX 9 at 13.95%, and Boeing 737-800 Passenger/BBJ2 (winglets) at 9.21%.

Best airlines flying from State of Washington to Illinois

Compare and see reviews for airlines that fly from State of Washington to Illinois with momondo

Airline	Rating	Free Cancellation	Price
Spirit Airlines	PriceFrom $93	Free Cancellation	Rating 6.3 8,027 reviews	Search Spirit Airlines flights
Delta	PriceFrom $119	Free Cancellation	Rating 7.9 7,980 reviews	Search Delta flights
Hawaiian Airlines	PriceFrom $121	Free Cancellation	Rating 7.8 2,679 reviews	Search Hawaiian Airlines flights
Frontier	PriceFrom $137	Free Cancellation	Rating 5.8 3,202 reviews	Search Frontier flights
United Airlines	PriceFrom $165	Free Cancellation	Rating 7.4 8,937 reviews	Search United Airlines flights
American Airlines	PriceFrom $169	Free Cancellation	Rating 7.2 10,000 reviews	Search American Airlines flights
Alaska Airlines	PriceFrom $170	Free Cancellation	Rating 8.0 10,000 reviews	Search Alaska Airlines flights
Southwest	PriceFrom $179	Free Cancellation	Rating 8.0 4,247 reviews	Search Southwest flights

Why use momondo?

Why should I use momondo to find a flight deal from Washington to Illinois?

It is quick and easy to find Washington to Illinois flights on momondo. We search and return numerous flight options from various airlines and agents. You can then use our filters to narrow your search until you have found the most convenient flight to Illinois that suits you.

Can I find flights from Washington to Illinois with flexible booking policies on momondo?

momondo does allow users to show only those flights to Illinois from Washington which offer a flexible booking policy as well as other useful filters and features.

How can momondo help me find flights from Washington to Illinois?

Once you have performed a search in the form on the page, momondo provides useful filters and insights. We can show you the cheapest days and times to fly as well as help filter your options to help you make an informed choice when booking flights to Illinois from Washington.

I’m not ready to book a flight from Washington to Illinois right now. Can momondo alert me if prices change?

If you are simply researching potential flights to Illinois, momondo offers a useful price alert feature which will track prices for flights to Illinois from Washington and alert you when they change.

An easier way to manage your Illinois trip

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Popular cities in Illinois

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Cheap flights from Washington to Illinois from $84

This is the cheapest one-way flight price found by a momondo user in the last 72 hours by searching for a flight from Washington to Illinois departing on 9/23. Fares may change, and may not be available for all flights or travel dates. Click the price to refresh the search for this deal.

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Hawaiian Airlines flights from State of Washington to Illinois

Our best Hawaiian Airlines deals on State of Washington to Illinois flight tickets

Spirit Airlines flights from State of Washington to Illinois

Our best Spirit Airlines deals on State of Washington to Illinois flight tickets

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How to get the cheapest flight ticket from State of Washington to Illinois

Look no further. We've gone through all the searches for this route on momondo so you have the important information and insights to find the cheapest flight ticket for your trip

What is the cheapest month to fly to Illinois?

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

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

Our most recent data shows that the best time of day to fly to Illinois is in the afternoon. Flights from State of Washington to Illinois during this time can be as low as $288. Flights in the morning are often more expensive with an average ticket price of $456.

What is the cheapest Washington to Illinois flight route?

Fly from Spokane to Chicago O'Hare Intl for the best Washington - Illinois flight prices

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

What cabin class options are available on Washington to Illinois flights?

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

Can stopping save me money on State of Washington to Illinois flights?

No. A direct flight is the cheapest option for a flight between State of Washington to Illinois.

What is the cheapest airline that flies from Washington to Illinois?

United Airlines, Frontier, and American Airlines are the most popular carriers operating from Washington to Illinois

What airlines fly to Illinois?

How many flights depart from State of Washington to Illinois on average per day?

103 flights are operational daily from State of Washington to Illinois as of August 2025. The most popular departure time for this route is 1:00PM, with 50% of flights per day taking off at noon.

How many flights depart from State of Washington to Illinois on average per week?

As of August 2025, 721 flights take off from State of Washington and land in Illinois each week. The most common flight departure day for this route is Sun, with 19% of weekly flights taking off on this day.

How long is the flight from State of Washington to Illinois?

Cheap State of Washington to Illinois flight deals and tips

Find info about flight duration, direct flights, and airports for your flight from State of Washington to Illinois

Best Price Found

Fastest flight time

Direct flights

Airports in Illinois

When did momondo last update prices for flights from Washington to Illinois?

How many operators does momondo search for flights from Washington to Illinois?

How old do you have to be to fly from Washington to Illinois?

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

What is the most popular plane model from State of Washington to Illinois?

Best airlines flying from State of Washington to Illinois

Compare and see reviews for airlines that fly from State of Washington to Illinois with momondo

Why use momondo?

Why should I use momondo to find a flight deal from Washington to Illinois?

Can I find flights from Washington to Illinois with flexible booking policies on momondo?

How can momondo help me find flights from Washington to Illinois?

I’m not ready to book a flight from Washington to Illinois right now. Can momondo alert me if prices change?

An easier way to manage your Illinois trip

We make it super easy to schedule, organize and travel with friends or family. Trips is free — and available to use no matter where you book.

Get notified when prices go down

Daily price changes in your inbox - only with Price Alerts.

Find better results for your trip to Illinois

Popular cities in Illinois

Popular flights according to clicks in the last 7 days on momondo