Cheap flights from San Diego to Seattle from $226 CLD, SAN → BFI, SEA

Found recently, and the cheapest we hold

What have prices looked like?

Over 46 days, 24 Sept to 11 Nov, the cheapest return we saw each day was $141 to $401.

Those were the prices on those days, not today's.

Could nearby dates be cheaper?

We hold no other 3-night return fares leaving within 3 days of 18 Dec to compare.

Every date we hold

7 fares on 4 departure dates

Which month looks cheapest?

December 2026 is the cheapest month — from $155.

Found recently, and the cheapest we hold

What have prices looked like?

Over 49 days, 24 Sept to 11 Nov, the cheapest one-way we saw each day was $55 to $94.

At $323, the cheapest one-way found recently is above that range.

Those were the prices on those days, not today's.

Could nearby dates be cheaper?

Yes. Among one-way fares leaving within 3 days of 24 Dec, 23 Dec costs $137: $186 less than the cheapest found recently.

Alaska Airlines · San Diego International Airport (SAN) → Seattle-Tacoma International Airport (SEA) · 1 stop · found 5 days ago

Open this tripCheck today's price

FareTell may earn a commission when you book through a partner.

Every date we hold

38 fares on 5 departure dates

Return

Fares 60 to 89 days before departure were typically 64% lower than 0 to 6 days before departure.

From the cheapest return each day between 24 Sept and 11 Nov (46 days), grouped by how many days ahead the flight left; one adult in economy.

Each range covers different departure dates, so this compares typical fares, not the same trip priced twice.

Prices reflect recent searches — current fares may differ.

One-way

Fares 30 to 59 days before departure were typically 22% lower than 14 to 29 days before departure.

From the cheapest one-way each day between 24 Sept and 11 Nov (49 days), grouped by how many days ahead the flight left; one adult in economy.

Each range covers different departure dates, so this compares typical fares, not the same trip priced twice.

Prices reflect recent searches — current fares may differ.

How much is a return flight from San Diego to Seattle?

The cheapest return found recently is $226 with Alaska Airlines, 18 Dec to 21 Dec, found 2 days ago. The cheapest return we hold, of any age, is $155 with Southwest Airlines, 12 Dec to 15 Dec, found 5 days ago. The cheapest return fare on each of 4 departure dates is usually $168 to $286.

How much is a one-way flight from San Diego to Seattle?

The cheapest one-way found recently is $323 with American Airlines, 24 Dec, found 4 days ago. The cheapest one-way we hold, of any age, is $90 with Southwest Airlines, 22 Dec, found 6 days ago. The cheapest one-way fare on each of 5 departure dates is usually $129 to $323.

What is the cheapest month to fly from San Diego to Seattle?

December 2026 is the cheapest month for a return, from $155, 12 Dec to 15 Dec, found 5 days ago.

How far ahead should I book a flight from San Diego to Seattle?

In 46 days of prices between 24 Sept and 11 Nov, return fares 60 to 89 days before departure were typically 64% lower than 0 to 6 days before departure. In 49 days of prices between 24 Sept and 11 Nov, one-way fares 30 to 59 days before departure were typically 22% lower than 14 to 29 days before departure.

Is there a direct flight from San Diego to Seattle?

Yes, the cheapest nonstop return found recently is $226 with Alaska Airlines, 18 Dec to 21 Dec, found 2 days ago. The cheapest nonstop one-way found recently is $140 with Alaska Airlines, 23 Dec, found 5 days ago.

How long is the flight from San Diego to Seattle?

The cheapest nonstop one-way found recently, with Alaska Airlines on 23 Dec, takes 3 h 17 min from San Diego International Airport (SAN) to Seattle-Tacoma International Airport (SEA). The cheapest one-way found recently, with American Airlines on 24 Dec, takes 8 h 3 min with 1 stop.

Which airlines have the cheapest flights from San Diego to Seattle?

Between 11 Dec and 11 Jun 2027, Southwest Airlines has the cheapest return on 2 of the 4 departure dates we hold, Alaska Airlines on 1 and United Airlines on 1. Between 20 Dec and 24 Dec, Frontier Airlines has the cheapest one-way on 1 of the 5 departure dates we hold, Envoy Air on 1 and Southwest Airlines on 1.