Cheap flights from Ontario, CA to Denver, CO

Flights starting at £18. Choose between Frontier Airlines, United Airlines, or Alaska Airlines to find the best price.

Make your travel wishlist, we'll do the rest
Hidden deals
Effortless booking
Travel hacking
Travelers usually depart from Ontario International, or Montclair (Ontario) when they travel from Ontario to Denver. Book your trip to arrive at Denver International, or Rocky Mountain Metropolitan Airport. The distance between Ontario and Denver is 1317 km. The most popular airlines for this route are Frontier Airlines, United Airlines, and Alaska Airlines. Ontario and Denver have 81 direct flights per week.

Weekly direct flights

Discover the top airlines offering direct flights from Ontario to Denver in the next month. You’ll find the number of daily direct flights per airline in the table.

Weekly direct flights for Mon 11.03 - Sun 17.03

AirlineMon 11.03Tue 12.03Wed 13.03Thu 14.03Fri 15.03Sat 16.03Sun 17.03
2332222
2222221

Weekly direct flights for Mon 18.03 - Sun 24.03

AirlineMon 18.03Tue 19.03Wed 20.03Thu 21.03Fri 22.03Sat 23.03Sun 24.03
2242222
2222231

Weekly direct flights for Mon 25.03 - Sun 31.03

AirlineMon 25.03Tue 26.03Wed 27.03Thu 28.03Fri 29.03Sat 30.03Sun 31.03
2222222
2222231

Weekly direct flights for Mon 01.04 - Sun 07.04

AirlineMon 01.04Tue 02.04Wed 03.04Thu 04.04Fri 05.04Sat 06.04Sun 07.04
2222222
2222231

Check-in for a flight from Ontario to Denver

NameCarrier codeIATA CodePassport needed during bookingOnline check-in available
Frontier AirlinesFFTF9NoOpens 24 days before flight
Closes 1 hours before flight
United AirlinesUALUAYesNo
Alaska AirlinesASAASNoOpens 24 days before flight
Closes 1 hours before flight

Weather in Denver

Average Weather

MonthAverage monthly max temperatureAverage monthly min temperature
January4°C-6°C
February4°C-6°C
March10°C-2°C
April13°C1°C
May18°C6°C
June26°C12°C
July29°C16°C
August28°C15°C
September25°C11°C
October17°C4°C
November10°C-1°C
December4°C-6°C
Hottest Month
29°C
July
Coldest month
-6°C
January
Sunny days
260
days per year
Snow days
26
days per year

14 day forecast

Thursday
14 Mar
99%
0°C0°C
21 Mar
18°C7°C
Friday
15 Mar
85%
2°C0°C
22 Mar
76%
11°C7°C
Saturday
16 Mar
84%
4°C-3°C
23 Mar
18°C6°C
Sunday
17 Mar
87%
7°C2°C
24 Mar
60%
20°C9°C
Monday
18 Mar
13°C1°C
25 Mar
88%
14°C7°C
Tuesday
19 Mar
16°C4°C
26 Mar
72%
12°C7°C
Wednesday
20 Mar
16°C6°C
27 Mar
10°C5°C

Frequently asked questions

How long does it take to travel from Ontario to Denver?
What is the flight distance between Ontario and Denver?
What airlines offer nonstop (direct) flights between Ontario and Denver?
What are the most popular routes to and from Ontario?
What are the most popular routes to and from Denver?
What airports are near Ontario?
What airports are near Denver?
Is it possible to combine flights, buses, and trains in one itinerary when traveling between Ontario and Denver?
What is Virtual Interlining and how do I use it?
Which airlines fly between Ontario and Denver?
When's the best time to travel between Ontario and Denver?
What flights operate between Ontario and Denver?
How many airports are there near Ontario?
How many airports are there near Denver?
What time do nonstop (direct) flights between Ontario and Denver depart?
What time do nonstop (direct) flights between Ontario and Denver arrive?
What time do flights between Ontario and Denver depart?
What time do flights between Ontario and Denver arrive?

Explore alternative trips

Flights from Ontario

Flights to Denver

Popular routes

Find the best connection from Ontario to Denver
Search flights, trains & buses
We hack the system,
you fly for less