Lowest fare in our latest check
St. Louis (STL) to San Juan (SJU): $396 round trip in December on United, 2 stops
Sample dates Dec 15 to Dec 22 · checked Oct 22 · fares change daily
Set a free price alert for STL to SJU →What STL to San Juan costs, from our daily checks
Lowest fare found each day for a 7-night round trip leaving Dec 15, economy, in USD. How we measure
9 observations since Oct 4. Price bands appear after 10 daily checks spanning 14 days.
Fare by month, STL to SJU
Of the 6 months we priced (November to April 2027), November had the lowest observed fare at $318 (checked Oct 18) and March 2027 the highest at $561, each for a 7-night trip from the 15th.
| Month | Lowest observed | Trip priced | Checked | Alert |
|---|---|---|---|---|
| November | $318Frontier | Nov 15 to Nov 22 | Oct 18 | Alert me under $270 |
| December | $396United | Dec 15 to Dec 22 | Oct 22 | Alert me under $330 |
| January 2027 | $511American | Jan 15 to Jan 22 | Oct 18 | Alert me under $430 |
| February 2027 | $436Southwest | Feb 15 to Feb 22 | Oct 18 | Alert me under $370 |
| March 2027 | $561United | Mar 15 to Mar 22 | Oct 18 | Alert me under $470 |
| April 2027 | $436American | Apr 15 to Apr 22 | Oct 18 | Alert me under $370 |
Alert targets are 15% under the observed fare, rounded down to $10. Each month is the same 7-night trip from the 15th.
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From STL airport to San Juan
Reaching St. Louis Lambert International
MetroLink light rail runs from downtown St. Louis to the airport terminals (Gateway Station) every 10-15 minutes, 24/7, taking 27 minutes from Civic Center Station; costs $3.50 one-way or $6 round-trip—this is your best bet. Uber/Lyft from downtown runs $18-28 depending on surge, and rideshare pickup is well-organized at Terminal 1. Rental cars and taxis available but unnecessary for most travelers. Parking at the airport: Hourly Garage runs $3/hour ($18 max daily), Economy Lot B is $12/day, and premium valet is $30/day—if you're leaving the car for 4+ days, the economy lot makes sense.
Getting from SJU into San Juan
Luis Muñoz Marín International (SJU) is about 7 miles east of Old San Juan. Option 1: Uber/Lyft to Condado runs $12–18 (10 min), to Old San Juan $18–28 (20–30 min) — download the apps before you land because they work seamlessly here. Option 2: The Metropolitan Bus Authority (AMA) Route C45 runs from the airport terminal to Isla Verde and Condado for $0.75 — it's slow (45–60 min) and you need exact change, but it works fine with light luggage. Option 3: Taxis from the official taxi stand use fixed zone fares — $12 to Isla Verde, $19 to Condado, $24 to Old San Juan, posted on signs at the stand. Avoid unmarked cabs at the curb. Car rental is available at the airport and highly recommended if you plan to visit El Yunque or the west coast.
Planning St. Louis to San Juan
San Juan is the Caribbean's most underrated city for Americans, and the passport-free angle is just the beginning. This is a place where you can eat world-class mofongo at midnight, swim in bioluminescent bays, walk 500-year-old cobblestone streets, and still catch a direct flight home — all without currency exchange or customs. The food scene alone justifies the trip: Old San Juan has more Michelin-recognized restaurants per square mile than most American cities, and local spots like El Jibarito have been serving the same perfect alcapurrias for decades.
Local basics
Best-month weather in San Juan
February
69–83°F · 11 rain daysThe driest month of the year and arguably the best weather window. Strong trade winds keep humidity low and the ocean turquoise.
March
70–84°F · 12 rain daysStill excellent conditions with warming temps and low rain. Spring break crowds arrive mid-month and hotel prices spike accordingly.
The destination guide flags September and August as the least favorable months.
Two areas to consider
Old San Juan (OSJ)
mid-rangeThe historic walled city is the only place in the Caribbean that genuinely competes with European old towns — 16th-century Spanish colonial buildings painted in pastels, with El Morro fort anchoring one end. Stay here if you want to walk everywhere: the best restaurants (Parcha, 1919, Marmalade), the rum bars on Calle San Sebastián, and the forts are all within a 10-minute walk. Hotel El Convento ($280–400/night) is the splurge worth making; Fortaleza suites have rooftop terraces overlooking the bay.
Condado
luxuryThe main resort strip with proper beach infrastructure, the Condado Vanderbilt ($400–600/night), and a decent walkable restaurant scene on Ashford Avenue. It's more Miami Beach than Caribbean authenticity, but the beach is gorgeous and easier to navigate than Isla Verde. La Concha Resort is the fun party hotel here; La Casita de Rones on Calle Condado has 300+ rum selections if you want to go deep on Puerto Rican spirits.
Local planning tip
Book your bio bay tour through Kayak Caño Gande in Fajardo rather than any Old San Juan tour operator — you'll pay $45 instead of $85–120 and the guide is a local fisherman who grew up on the bay. Go on a new moon night (check the lunar calendar before you book) when there's zero ambient light; the bioluminescence is 10x more dramatic than on a full moon night and most tour operators won't tell you this because they sell tours regardless of moon phase. Also: the Lote 23 food truck park in Santurce is open Thursday–Sunday evenings and has the best casual eating in the city at $8–14 per dish — it's where San Juan's chefs eat on their nights off.
Visa and entry notes for US travelers
Puerto Rico is a US territory — American citizens need zero documentation beyond a valid US ID or passport. No customs, no immigration, no visa of any kind. You're effectively flying domestic. Your phone works on your existing plan (it's the same as flying to Florida), your credit cards work everywhere, and there's no currency exchange. Non-US citizens travel to Puerto Rico under the same rules as entering the US mainland — if you have a valid US visa or are from a Visa Waiver Program country, you're fine. If you need a US visa, that same visa covers Puerto Rico entry.
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Lowest live fare: Charlotte (CLT), $253 round trip, checked Oct 22