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Find cheap flights from San Diego to Boulder from $35

This is the cheapest one-way flight price found by a KAYAK user in the last 72 hours by searching for a flight from San Diego to Boulder departing on 6/15. Fares are subject to change and may not be available on all flights or dates of travel. Click the price to replicate the search for this deal.
1 adult
0 bags
Fri 6/7
Fri 6/14

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Good to know

Low season

January

High season

June

Cheapest flight

$35
Best time to beat the crowds with an average 21% drop in price.
Most popular time to fly with an average 26% increase in price.
Flight from San Diego to Denver

When to book flights from San Diego to Boulder

Are your dates flexible? Find out the best times to travel from San Diego to Boulder based on our flight data from the last year. Discover the cheapest month and even day to fly.
Estimated round-trip price

FAQs for booking flights from San Diego to Boulder

  • Which airports will I be using when flying from San Diego to Boulder?

    When flying out of San Diego you’ll be using San Diego. Boulder does not have its own airport so you’ll be flying into nearby Denver Intl airport, which is 33.4 mi away.

  • How long does a flight from San Diego to Boulder take?

    Direct flights cover the 852 miles separating San Diego and Boulder in about 2h 23m.

  • How many flights are there between San Diego and Boulder?

    39 direct flights run between San Diego and Boulder on a daily basis. On average, there are about 276 departures each week.

  • What’s the cheapest day of the week to fly between San Diego and Boulder?

    Consider leaving on a Tuesday and avoid Mondays if you are looking for the best rates. For your return to San Diego, you’ll find the best rates on Tuesdays and the most expensive ones on Mondays.

  • How does KAYAK find such low prices on flights from San Diego to Boulder?

    KAYAK is a travel search engine. That means we look across the web to find the best prices we can find for our users. With over 2 billion flight queries processed yearly, we are able to display a variety of prices and options on flights from San Diego to Boulder.

  • How does KAYAK's flight Price Forecast tool help me choose the right time to buy my flight ticket from San Diego to Boulder?

    KAYAK’s flight Price Forecast tool uses historical data to determine whether the price for a flight to Boulder from San Diego is likely to change within 7 days, so travelers know whether to wait or book now.

  • What is the Hacker Fare option on flights from San Diego to Boulder?

    Hacker Fares allow you to combine one-way tickets in order to save you money over a traditional round-trip ticket. You could then fly to Boulder with an airline and back to San Diego with another airline.

  • What is KAYAK's "flexible dates" feature and why should I care when looking for a flight from San Diego to Boulder?

    Sometimes travel dates aren't set in stone. If your preferred travel dates have some wiggle room, flexible dates will show you all the options when flying to Boulder from San Diego up to 3 days before/after your preferred dates. You can then pick the flights that suit you best.

  • Which airlines provide the cheapest flights from San Diego to Boulder?

    In the last 72 hours, the cheapest one-way ticket between San Diego and Boulder found on KAYAK was with Frontier for $35. Frontier offered a round-trip connection from $61 and Delta from $196.

See more FAQs

Top tips for finding cheap flights from San Diego to Boulder

  • There is no airport in Boulder. Instead, you’ll be flying into Denver Airport when flying between San Diego and Boulder.
  • The cheapest flight from San Diego to Boulder was found 56 days before departure, on average.
  • Book at least 1 week before departure in order to get a below-average price.
  • High season is considered to be June, July and August. The cheapest month to fly is April.
See more tips

Top 5 airlines serving San Diego to Boulder

 
Need help choosing which airline to fly with from San Diego to Boulder? KAYAK airline reviews give an overall score for each airline based on loads of factors, including comfort, boarding, in-flight entertainment and more, to make your decision easier. See airline scores according to verified KAYAK customer reviews.
8.0
DeltaOverall score based on 10789 reviews
7.9Comfort
8.6Crew
8.0Entertainment
7.4Food
8.2Boarding
Airline reviews

I'm a larger, athletic guy (6'2", 260lbs powerlifter) and I found the seats incredibly uncomfortable with minimal leg room, especially in a window seat. Now, I full understand that being smaller may change my view but even if I was 80lbs less, my legs would be the same size and I was sandwiched between my seat and the seat in front of me.

6.0 GoodDan, Apr 2024LGA - DEN
Read more about Delta reviews

I'm a larger, athletic guy (6'2", 260lbs powerlifter) and I found the seats incredibly uncomfortable with minimal leg room, especially in a window seat. Now, I full understand that being smaller may change my view but even if I was 80lbs less, my legs would be the same size and I was sandwiched between my seat and the seat in front of me.

There was a loud squeaky sound the whole time we were flying.

I didn’t not like that I could not select my seat and ended up with the worse seat.

The landing was bad and the hostess came two times and i was sleeping but when she served the person that nexts to me I woke up and she didn’t even asked me if I need any drink or snacks two times!!!!

The helpful attitude of the staff, and being a wheelchair passenger everyone was helpful and understanding. The trip was made comfortable by the upgraded seat which was given without my request, that was a great surprise. Thank you Delta.

Plane was late because of a mechanical malfunction and the food listed as available was not. Flight attendants seem over worked and under paid. They just done seem happy. And that can be seen in their faces.

Waited 3 hours on a plane to de-ice due to manpower issues. Waited another hour and a half once we landed because of a gate issue. Missed my connections. Created. A total of 13 hours of delay.

Great, on time departure, friendly and accommodating crew, great leg room, Smith flight

Plane was turned around due to fog half way into the flight, Delta did not properly direct passengers to stay on same flight and instead failed to properly rebook on Alaska

Like most domestic flights in the US, you are basically on your own with this airline when it comes to food, so be sure to purchase meals and drinks ahead of time or expect to arrive starving and dehydrated (like I was).

I paid $380 for my one-way ticket from California to Minnesota. The fair did not include online check-in. I received instructions from their app to check in at a kiosk. At the kiosk, the boarding pass would not print until an actual person came to verify that I had a personal item and not a carry-on item, On the plane, the person next to me was drunk and allowed to continue to order alcohol. United is garbage I’d rather fly spirit.

The plane was dirty and the in seat air wasn't blowing as planes usually do.

Do not like the feeling of being in the basic economy. Everyone should feel good no matter what.

Positive: Entertainment via phone on the short was great and my first time. Good food and wine and head phones for free. Negative: Seat hardly reclined on the long flight. Breakfast was an egg with a bun. No egg choices and rather have something sweet like bun/jam and Youghurt.

They did get us booked on a later flight, but it made us miss our connecting flight. So, we had to stay and another state overnight with no luggage or clothes. Because they kept our luggage at airport for next flight on the next day.

Flight was on time. Staff were friendly. I paid for Economy Plus but was required to check my standard carry-on luggage due to lack of space on the aircraft. This cost me 30 minutes, unexpectedly, in waiting at the baggage claim. This experience did not meet my expectations.

Crew is way too many times on the intercom re explaining the same thing

Amazing comfortable chairs great snacks super friendly staff pilots did excellent job. Smooth sailing all the way. Definitely be flying United more.

We waited too long to get water while the plane was on the Tarmac awaiting de-icing.

Easy peasy. Crew was great. Take-off and landing nice anc chill (good job by the pilot). Thank you UA!

Horrible - they lied to me about baggage & boarding, even though I specifically spoke to their agents the day before my flight about my issue. When I showed up they did not let me board and stranded me at my airport until I bought a new flight with money I did not have to spend.

The experience was great and much better than the flight going out. of course I was in first class but the service was excellent

Comfort of seats, ease of boarding. Food selection could be better

Food options were limited which is absolutely embarrassing for a Flight of this size The staff did not come around as much and I am not accustomed to such poor service from American Airlines Drinks I believe were limited to soda and water

Because I can’t stand very long in one place, I was allowed to reword.

Crew were attentive and friendly. Flight was smooth and early! I enjoyed the less crowded plane. Thank you!

We are gluten free, there were not any available complimentary gluten free options.

No meal on a cross country flight? SFO-MiA is pretty much the definition of a coast to coast flight. No meal provided. Sky high wi-fi rates too. Stop nickel and diming your customers.

The staff was unprofessional and didn’t communicate very well. The boarding process was very disheveled, potentially due to a power outage the previous day but there was no contingency plan to properly get passengers boarded the following day. Once boarded the aircraft stayed on the tarmac for over 45 minutes due to high winds. The communication was sporadic but an announcement was finally made an additional 30 minutes later that the flight was cancelled but we couldn’t get off the plane. Prior to deplaning one of the gate agents came on the plane and made an announcement for everyone to pickup their checked bags and take a card to rebook a new reservation because they didn’t have adequate staff. Flights were missed, passengers went to different airports and there was little to no assistance from AA.

Apart from the delay due to unforeseen circumstances. The leg from sjc to dfw was fine. It was the leg from dfw to orf that we encountered issues mainly due to the flight attendant crew not being friendly. We had two small children and we needed some assistance to warm up milk so the baby would sleep. The crew just didn’t get it and made things very difficult. One made a remark that the baby’s dirty diaper smell was a “gift” to the plane in a rude way. Normally I’d brush that off as a funny comment if the rest of the trip the attendants were helpful or understanding of the difficulty we faced. But that wasn’t the case. We were met with rudeness on the second leg. Whereas on the first leg the crew were so nice and helpful.

Overall it was a miserable experience... I will never fly spirit for more than a 3 hour flight or overnight.

Kayak does not know that spirit airlines charged me $70 to fly. But the bag check-in was $89 each way. This is false advertising to lure people. Spirit airlines sends bunch of emails after flight purchases to buy wifi, better seats, priority boarding, secure reserved seats. This is false advertising. Up front pricing. I would of flown jet blue or Alaska airlines.

One hour late taking off. Concerning, very hard landing. Uncomfortable seats with no recline. Extremely slow baggage claim. Very professional, knowledgeable flight attendants. Brand new, very clean plane.

Can’t say there was anything I particularly liked. Seats were very tight, leather wrapped plastic. I followed up a much longer and cheaper trip from Honolulu on southwest, everything was phenomenal, this flight was the exact opposite. Blows my mind they charge for water of all things. One of the attendants seemed very rude, I watched a taller gentleman a couple rows forward with his knees pressed into the back of the seat ahead, while the woman in that seat leaned forward the entire flight, I’m sure because she could feel his knees. I’ll be avoiding spirit like the plague from here forward.

Didn’t make the connecting flight due to a delay on our first flight.

I felt scam to have to pay $50 additional for my carry on luggage which was free for my other airline.

Enjoyed the experience, on time flights, friendly staff the WiFi was intros d kept cutting out.

Awful experience. Both flights were delayed several times with weather but also crew members being the official cause. The vouchers are unusable and insufficient ($50 voucher to fly the same crappy airline is a joke for putting me on a red-eye that landed at 3:00 am). The aircrafts were old and uncomfortable (have a real pocket on the seat, for crying out loud!).

Its so random that they only allow 40 pounds on checked bags when all airlines take 55. They then charge you for each 10 extra pounds, so my checked suitcase was $130 and the flight $30 ... its like whattt, im for sure not traveling with Spirit again

It wasn’t as horrible as I would have expected, however, to not provide water and change so much for bags is a ripoff to say the least.

Didn't like anything!! Horrible flight. Small seating area and hard seats. Butt was sore after 2 hour flight to Seattle No entertainment or free refreshments No wifi or USB charging receptacles to charge phone entoute like other airliners Luggage rates were 3 times as much as competitors. Difficult to navigate online luggue process to pre pay before flight Overall bad experience WILL NEVER RIDE OR RECOMMEND FRONTIER TO FRIENDS OR FAMILY MEMBERS!!! THIS IS A SHAME!! MOST MESERIBLE FLIGHT OF MY LIFE!! AND I THOUGHT SPIRIT WAS 👎 YOU GOT THEM BEAD HANDS DOWN!!

There were 3 leg for the trip and each leg was delayed by 90 minutes or more. The boarding process takes forever with people waiting on the jetway even though most folks do not have carry-on. The whole process is poorly managed.

Not have to pay for every single item to take a flight. Seating and delays sucked.

Terrible. Seats are bad and the baggage policy is inconsistent

Everything was good, and most importantly on time. They have been extremely tardy in some of my flights

They lost my baggage on my connection flight, it’s been 24 hours since I put my claim in and still no update on my bags.

It’s a cheap airline. I wish they had better seats.

The only issues had were outside of Frontier’s control or weren’t expected. It was a two hour flight they completed fast. We landed almost an hour ahead of schedule. The issues with no entertainment or food weren’t issues since there was no expectations. The issue of the loud or crying babies was outside of frontiers control.

My first time to fly Frontier and loved it! Boarding was super easy as we only had personal items. Crew was helpful and funny and the plane was clean. Pilot was also great at landing the plane smoothly.

Seats are cramped and very uncomfortable. You have to pay for everything and it is too expensive.

Book cheap flights from San Diego to Boulder

Recent round-trip flight deals

6/4Tue
nonstopFrontier
2h 30mSAN-DEN
6/11Tue
nonstopFrontier
2h 28mDEN-SAN
$61
6/8Sat
nonstopFrontier
2h 26mSAN-DEN
6/15Sat
nonstopFrontier
2h 30mDEN-SAN
$63
5/29Wed
nonstopFrontier
2h 28mSAN-DEN
6/4Tue
nonstopFrontier
2h 31mDEN-SAN
$64
7/16Tue
nonstopFrontier
2h 34mSAN-DEN
7/23Tue
nonstopFrontier
2h 23mDEN-SAN
$65
8/6Tue
nonstopFrontier
2h 34mSAN-DEN
8/10Sat
nonstopFrontier
2h 23mDEN-SAN
$66
6/4Tue
nonstop
2h 28mSAN-DEN
6/11Tue
1 stop
7h 05mDEN-SAN
$115
6/2Sun
1 stop
16h 15mSAN-DEN
6/6Thu
nonstop
2h 28mDEN-SAN
$141
5/29Wed
1 stopDelta
6h 39mSAN-DEN
6/4Tue
1 stopDelta
4h 09mDEN-SAN
$196
6/1Sat
1 stopDelta
4h 58mSAN-DEN
6/5Wed
1 stopDelta
4h 45mDEN-SAN
$202
5/25Sat
nonstopUnited Airlines
2h 26mSAN-DEN
5/27Mon
1 stopUnited Airlines
5h 15mDEN-SAN
$258

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Recent one-way flight deals

6/15Sat
nonstopFrontier
2h 27mSAN-DEN
$35
6/18Tue
nonstopFrontier
2h 35mSAN-DEN
$37
6/1Sat
1 stopDelta
4h 58mSAN-DEN
$98
6/10Mon
2 stops
22h 15mSAN-DEN
$105
8/5Mon
1 stopAmerican Airlines
4h 36mSAN-DEN
$114
6/10Mon
3 stops
25h 25mSAN-DEN
$116
6/28Fri
1 stopDelta
4h 39mSAN-DEN
$118
5/25Sat
1 stopAmerican Airlines
4h 32mSAN-DEN
$124
6/17Mon
nonstopUnited Airlines
2h 30mSAN-DEN
$139
8/6Tue
2 stopsUnited Airlines
12h 14mSAN-DEN
$222

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Last minute flights from San Diego to Boulder

Last minute flight, train and bus deals

5/13Mon
nonstopFrontier
2h 34mSAN-DEN
5/14Tue
nonstopFrontier
2h 31mDEN-SAN
$149
5/13Mon
nonstopFrontier
2h 23mSAN-DEN
5/15Wed
nonstopFrontier
2h 33mDEN-SAN
$160
5/13Mon
nonstopFrontier
2h 34mSAN-DEN
5/16Thu
nonstopFrontier
2h 29mDEN-SAN
$169
5/13Mon
nonstop
2h 24mSAN-DEN
5/16Thu
multi-stop
6h 30mDEN-SAN
$353
5/10Fri
nonstop
2h 32mSAN-DEN
5/14Tue
multi-stop
7h 45mDEN-SAN
$373
5/11Sat
nonstopUnited Airlines
2h 26mSAN-DEN
5/15Wed
multi-stopUnited Airlines
5h 36mDEN-SAN
$474
5/13Mon
multi-stopUnited Airlines
4h 43mSAN-DEN
5/15Wed
multi-stopUnited Airlines
4h 37mDEN-SAN
$481
5/13Mon
multi-stopDelta
4h 42mSAN-DEN
5/14Tue
multi-stopDelta
4h 18mDEN-SAN
$496
5/10Fri
multi-stopDelta
6h 39mSAN-DEN
5/12Sun
multi-stopDelta
4h 19mDEN-SAN
$626
5/9Thu
multi-stopAmerican Airlines
10h 52mSAN-DEN
5/11Sat
multi-stopAmerican Airlines
9h 26mDEN-SAN
$2,376

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