In terms of precipitation, rainfall in Illinois ranges from 43.0 - 125.0 inches per month. August is typically the wettest month, when rainfall can reach 125.0 mm. January is typically the driest time to visit Illinois when rainfall is around 43.0 mm.

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 23.0 C. Travellers hoping to avoid the cold should look outside of January, when temperatures are typically at their lowest (around -5.0 C).

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

When flying from Belfast Intl Airport 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.

Can I find deals for flights from Belfast Intl to Illinois that include hotel bookings?

Yes. In addition to deals on Belfast Intl to Illinois flights, Cheapflights offers holiday packages that include both flights and hotel.

How can I find direct flights from Belfast Intl to Illinois?

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

Can I find deals for business class flights from Belfast Intl to Illinois?

Yes. Cheapflights offers flight deals from Belfast Intl 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.

£398+ Cheap Flights from Belfast Intl Airport to Illinois

Cheap flight deals from Belfast Intl to Illinois

Enter your travel dates to find the best prices.

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Cheapest flights from Belfast Intl to Illinois
Explore the most affordable flight options available from Belfast Intl to Illinois. Find the lowest fares from popular airlines and budget airlines, with prices last updated on 5 September 2026.

Fri 2/1021:10 -

2 stops25h 43m

Sun 4/1022:25 -

2 stops16h 35m

Deal found 1/9£657

Thu 10/908:20 -

2 stops16h 55m

Mon 14/921:00 -

2 stops17h 40m

Deal found 31/8£719

Sun 18/1014:40 -

2 stops27h 55m

Sun 25/1019:30 -

2 stops21h 10m

Deal found 3/9£755

Thu 1/1008:20 -

2 stops15h 55m

Mon 5/1019:25 -

2 stops14h 50m

Deal found 1/9£757

Find flight deals from Belfast Intl to Illinois

Round-trip from	£657
One-way from	£398

2/10-4/10
4 total stops
42h 18m total
Belfast to Illinois

Search Deals

3/10-31/12
2 total stops
18h 53m total
Belfast to Illinois

Search Deals

Cheapflights Fare Finder

Use the filters below to find and compare flights from Belfast Intl Airport to Illinois that are best for you.

Fly from

Fly to

Route

Depart

Return

Price

Cheapest return flight

Fastest return journey

BelfastChicago

BFS Belfast Intl - ORD Chicago O'Hare Intl

BFSORD

Belfast Intl

Sat 3/10

06:55-19:48

2 stops18h 53m

Chicago O'Hare Intl

Wed 31/12

00:00-07:00

Nonstop0h 00m

£398

BelfastChicago

BFS Belfast Intl - ORD Chicago O'Hare Intl

BFSORD

Belfast Intl

Fri 2/10

21:10-16:53

2 stops25h 43m

Chicago O'Hare Intl

Sun 4/10

22:25-23:35

3 stops19h 10m

£679

BelfastChicago

BFS Belfast Intl - ORD Chicago O'Hare Intl

BFSORD

Belfast Intl

Sun 18/10

14:40-12:35

2 stops27h 55m

Chicago O'Hare Intl

Sun 25/10

19:30-21:40

2 stops21h 10m

£755

BelfastChicago

BFS Belfast Intl - ORD Chicago O'Hare Intl

BFSORD

Belfast Intl

Thu 1/10

08:15-19:50

2 stops17h 35m

Chicago O'Hare Intl

Mon 5/10

19:25-23:20

3 stops21h 55m

£859

Flights are sorted by cheapest return flights first.

Deals found on 3/9

Sorted by cheapest first

Best time to book a flight from Belfast Intl to Illinois

Have a flexible travel schedule? Discover the best time to fly to Illinois from Belfast Intl with our price prediction graph.

BFS-ORD

Estimated return 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.

Cheapflights Insights

Everything you need to know about your flight from Belfast Intl Airport to Illinois

BFS-USIL

BFS-ORD

No data available for this route at this time. Please check back soon.

Related info for your journey

Can I find deals for flights from Belfast Intl to Illinois that include hotel bookings?
Yes. In addition to deals on Belfast Intl to Illinois flights, Cheapflights offers holiday packages that include both flights and hotel.
How can I find direct flights from Belfast Intl to Illinois?
After entering your origin and destination, apply the non-stop filter on the search result page to find direct flights from Belfast Intl to Illinois.
Can I find deals for business class flights from Belfast Intl to Illinois?
Yes. Cheapflights offers flight deals from Belfast Intl 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.

Browse thousands of different options on Cheapflights for your next trip

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By finding flights from multiple airlines and providers at completely no cost, Cheapflights helps millions of users like you annually find the best flights to Illinois from Belfast Intl.

Can Cheapflights find flights from Belfast Intl to Illinois with no change fees?

Need flexible booking options for your flight to Illinois from Belfast Intl? Don’t worry, Cheapflights have you covered. Use our search filter to only show flights with no change fees.

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Cheap flights from Belfast Intl Airport to Illinois from £398

This is the cheapest retur flight price found by a Cheapflights user in the last 72 hours by searching for a flight departing on 3/10. Fares are subject to change and may not be available on all flights or dates of travel.

Cheap flight deals from Belfast Intl to Illinois

Cheapest flights from Belfast Intl to IllinoisExplore the most affordable flight options available from Belfast Intl to Illinois. Find the lowest fares from popular airlines and budget airlines, with prices last updated on 5 September 2026.

Explore the most affordable flight options available from Belfast Intl to Illinois. Find the lowest fares from popular airlines and budget airlines, with prices last updated on 5 September 2026.

Best flights from Belfast Intl to IllinoisDiscover carefully curated flight deals from Belfast Intl to Illinois that have cost, travel time, and stopovers in mind to ensure you get the best travel experience. Data last updated 5 September 2026.

Discover carefully curated flight deals from Belfast Intl to Illinois that have cost, travel time, and stopovers in mind to ensure you get the best travel experience. Data last updated 5 September 2026.

Last-minute flights from Belfast Intl to IllinoisDiscover last-minute flight deals from Belfast Intl to Illinois. Data last updated 5 September 2026 and is based on user searches.

Discover last-minute flight deals from Belfast Intl to Illinois. Data last updated 5 September 2026 and is based on user searches.

One-way flights from Belfast Intl to IllinoisSearch for one-way flight options from Belfast Intl to Illinois. Find affordable one-way fares based on user searches. Data last updated 5 September 2026.

Search for one-way flight options from Belfast Intl to Illinois. Find affordable one-way fares based on user searches. Data last updated 5 September 2026.

Find flight deals from Belfast Intl to Illinois

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Use the filters below to find and compare flights from Belfast Intl Airport to Illinois that are best for you.

Best time to book a flight from Belfast Intl to Illinois

Have a flexible travel schedule? Discover the best time to fly to Illinois from Belfast Intl with our price prediction graph.

Cheapflights Insights

Related info for your journey

Can I find deals for flights from Belfast Intl to Illinois that include hotel bookings?

How can I find direct flights from Belfast Intl to Illinois?

Can I find deals for business class flights from Belfast Intl to Illinois?

Browse thousands of different options on Cheapflights for your next trip

Toggle through the tabs below to find thousands of options on Cheapflights for your next trip.

Alternative routes for Belfast Intl to Illinois

See prices for flight routes from nearby airports that may be better suited for you.

Complete your trip

Complete your trip to Illinois by adding a car hire and/or hotel booking to your travel itinerary.

Direct flights to United States

Book a non-stop flight to one of these other cities located in United States.

Search flights from Belfast Intl to Illinois by cabin class

Find flights from Belfast Intl to Illinois, based on your preferred cabin class, be it economy, premium economy, business, or first class.

Belfast Intl and Illinois flights

Browse other Belfast Intl and Illinois flight options. Last updated on 5 September 2026.

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How does Cheapflights help users find flights from Belfast Intl to Illinois?

Why should you use Cheapflights to find cheap flight tickets from Belfast Intl to Illinois?

Can Cheapflights find flights from Belfast Intl to Illinois with no change fees?

Can Cheapflights notify me if prices for flights from Belfast Intl to Illinois become cheaper?

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Book with Flexibility

Travel Smart

Cheapest flights from Belfast Intl to Illinois
Explore the most affordable flight options available from Belfast Intl to Illinois. Find the lowest fares from popular airlines and budget airlines, with prices last updated on 5 September 2026.

Best flights from Belfast Intl to Illinois
Discover carefully curated flight deals from Belfast Intl to Illinois that have cost, travel time, and stopovers in mind to ensure you get the best travel experience. Data last updated 5 September 2026.

Last-minute flights from Belfast Intl to Illinois
Discover last-minute flight deals from Belfast Intl to Illinois. Data last updated 5 September 2026 and is based on user searches.

One-way flights from Belfast Intl to Illinois
Search for one-way flight options from Belfast Intl to Illinois. Find affordable one-way fares based on user searches. Data last updated 5 September 2026.