St Louis to San Francisco in September 2026

Dated one-way fares from St Louis to San Francisco in September 2026. Use the calendar to see which days are cheaper.

Lowest this month $142

Highest this month $158

Sample fare $142

Airports STL–SFO

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September 2026 price calendar

From $142 · up to $158

Mon

Tue

Wed

Thu

Fri

Sat

Sun

22 $142 23 $150 24 $150 25 $150 26 $158

San Francisco SFO

$142

Sep 22, 12:17pm · 24h 5m · 3 stops

STL → SFO · Frontier Airlines

San Francisco SFO

$158

Sep 26, 12:17pm · 8h 7m · 1 stop

STL → SFO · Frontier Airlines

This page is only September 2026 on the St Louis to San Francisco route. Open the full route if you want the next months side by side.

Prices move as seats sell. Confirm the live itinerary before you book St Louis to San Francisco in September 2026.