United Flight 540 Deals & Information (2025/2026)

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United Flight 540 Route Deals From $99

The cheapest prices found with in the last 7 days for return flights were $149 and $99 for one-way flights to San Diego Intl. for the period specified. Prices and availability are subject to change. Additional terms apply.

Tue, May 27 - Sat, Jun 7
DEN
Denver Intl.
SAN
San Diego Intl.
$149 Roundtrip, found 2 days ago
$149
Roundtrip
found 2 days ago
Select United flight, departing Tue, May 27 from Denver Intl. to San Diego Intl., returning Sat, Jun 7, priced at $149 found 2 days ago
Sat, May 31 - Sat, Jun 14
DEN
Denver Intl.
SAN
San Diego Intl.
$170 Roundtrip, found 1 hour ago
$170
Roundtrip
found 1 hour ago
Select United flight, departing Sat, May 31 from Denver Intl. to San Diego Intl., returning Sat, Jun 14, priced at $170 found 1 hour ago
Wed, Jul 30 - Tue, Aug 5
DEN
Denver Intl.
SAN
San Diego Intl.
$197 Roundtrip, found 2 days ago
$197
Roundtrip
found 2 days ago
Select United flight, departing Wed, Jul 30 from Denver Intl. to San Diego Intl., returning Tue, Aug 5, priced at $197 found 2 days ago

Frequently asked questions

What route does flight number UA540 take?
You’ll be landing at SAN from Denver Intl. Airport (DEN) if you’ve booked a ticket on flight number UA540. You’ll be airborne for 2 hours and 26 minutes on this trip. It’s also good to note that the service conveniently operates non-stop.
How often is UA540 on time?
People jetsetting on United Airlines flight number UA540 should be mindful that 76% of these flights depart as scheduled. If your trip experiences a delay, the typical wait is approximately 18 minutes. This route has a star rating of 2.2.
What kind of plane is on flight number UA540?
Prepare to jump on board a Boeing 737-800 if you have a seat on flight UA540. Most services from DIA airport to San Diego Airport use this model of aircraft.
If I am not able to travel due to COVID-19, can I change my flight to a later date?
For more info about changing your UA540 flight with Travelocity, please visit our Customer Service Portal.