Uyuni Altitude Sickness: What Height You Face and How to Handle It

Uyuni Town and the Salar

Sources disagree slightly on Uyuni's elevation, and it is worth knowing the spread. Wikipedia gives 3,700 m for the town, 3,663 m for the salar surface, 3,665 m for Joya Andina airport, and operator pages commonly cite 3,656 m. Any of these figures puts you well above the 3,000 m line where the CDC's ascent rules start to apply.

The good news is the salar itself is flat to within less than one meter across its 10,582 km² surface, so walking on the salt costs no extra effort. Incahuasi Island sits at 3,656 m in the middle of the flat, and its short cactus trail climbs for only about 15-20 minutes. A one-day jeep loop like the Salt Flats Highlights Jeep Tour with Lunch keeps you in this band the whole time.

The CDC also warns against jumping from below 1,200 m to a sleeping altitude above 2,750 m in a single day, which is exactly what a flight from the coast to Uyuni does.

The High Points of the 3-Day Route

The southwest circuit through the Eduardo Avaroa reserve is a different animal. The reserve covers 714,745 hectares with altitudes between 4,200 m and 5,400 m. Laguna Colorada lies at 4,278 m, Laguna Verde at 4,310 m, and the lagoon chain of Cañapa, Hedionda and Chiar Khota runs roughly 4,100-4,700 m.

The Sol de Mañana geyser field is the day-three high point at about 4,900 m, though sources conflict: Wikipedia says about 4,900 m, some operators say 4,850 m, and a sign at the site reportedly reads about 4,905 m. Travelers crossing to Chile finish at the Hito Cajón pass at 4,480 m. Every one of these figures is at least 1,100 m above the CDC's 3,000 m threshold, and you sleep at Laguna Colorada on night two of routes that end back in Uyuni or at the border.

What the Fees Have to Do with It

The lagoons route crosses the Eduardo Avaroa reserve, and that is where the cash fees come in. Foreign visitors pay 150 Bs (about $13) at the reserve entrance and around 30 Bs (about $3) at Incahuasi Island, both in cash and both usually excluded from the tour price. The listing for the 3-Days Tour to the Uyuni Salt Flat and Colored Lagoons +Sunset+Mirror Effect prices at $290 but adds $62 of mandatory extras, so $352 per person, with park entrances and the sleeping bag still on top.

That price picture is separate from the health one, but the two meet in one place: the tour listing itself advises passengers with altitude sickness risk, pregnancy or back problems against this route. If you decide the high route is not for you, a one-day salar loop keeps you under 3,700 m and still shows you the flat. The one-day Uyuni salt flat tours keep the whole trip in that lower band.

The Ascent Rules

The CDC Yellow Book advises that above 3,000 m you should move your sleeping altitude by no more than about 500 m (1,650 ft) per night, and add an extra acclimatization night for every 1,000 m (3,300 ft) of further gain. It also warns against jumping directly from below 1,200 m to a sleeping altitude above 2,750 m in a single day. Now hold the standard 3-day Uyuni tour against that.

Night one is a salt hostel, or San Juan on one listing, and no elevation is published for either. Night two is at Laguna Colorada at 4,278 m. Measured from Uyuni town at 3,656-3,700 m, that is a gain of roughly 580-620 m in sleeping altitude, above the CDC's 500 m guidance.

The Protective Staging Fix

The CDC also gives the fix. Acclimatizing for a minimum of 2-3 nights at around 2,450-2,750 m before going higher is markedly protective against altitude illness. Nothing on the Uyuni circuit sits in that band.

Uyuni town, at 3,656-3,700 m, is already about 900 m above the top of it, and the sources used for this guide give no elevation for La Paz or Sucre, so check the figure for any staging town before you count on it. What the CDC rules do make clear is where your nights matter most. The guidance is built around sleeping altitude, and it asks for an extra night for every 1,000 m of further gain above 3,000 m.

A day tour that returns to Uyuni puts your bed back at 3,656-3,700 m that evening. The 3-day route moves your bed to 4,278 m on night two, and that step is the one to prepare for with extra nights in Uyuni first.

Symptoms and When They Are Serious

The sources behind this guide carry the CDC's ascent rules, not its symptom list, so this page gives no medical dosing advice. What the tour listings themselves state is the practical picture. The 3-Day Uyuni Salt Flats Tour ending in San Pedro de Atacama says it is not suitable for children under 3, pregnant women or people with back problems, and warns that the vehicle may occasionally stop briefly due to altitude.

The Andes Salt Expeditions lagoons listing advises against the route for passengers with altitude sickness risk, and the express tour from La Paz lists itself as not suitable for people with altitude sickness. If you feel worse at altitude, tell your driver early. On the southwest circuit the lowest ground in reach is Uyuni town at 3,656-3,700 m, a long jeep ride back, and the route forward to the border at 4,480 m is not lower.

From San Pedro to the 4,480 m Pass on Day One

The Chile-to-Bolivia direction puts the highest ground first. Chilean customs are completed in San Pedro town itself, about 45 km (28 mi) from the Hito Cajón pass, and Bolivian customs are processed at the pass summit at 4,480 m (14,700 ft). So a traveler who slept in San Pedro is standing at 4,480 m within the first hours of the tour.

On the 4-day round trip from San Pedro, the route order runs Laguna Blanca, Laguna Verde at 4,310 m, the Salvador Dalí Desert at about 4,750 m, the Polques hot springs at about 4,400 m and the Sol de Mañana geysers near 4,900 m, then Laguna Colorada at 4,278 m, all before the salar. The listing starts with an early morning pickup from your San Pedro hostel. There is no staging night at Uyuni's elevation on that route at all.

If you are planning that direction, the crossing logistics and alternatives are covered in the San Pedro de Atacama to Uyuni guide.

The Uyuni Direction Is Gentler

Running the route the other way around, from Uyuni to Chile, gives you the salar day first at 3,663 m, then a night at a salt hostel, then the climb to Laguna Colorada at 4,278 m. You gain altitude across two days instead of meeting the highest ground at the start. The Uyuni: 3-Day Salt Flats Tour ending in San Pedro de Atacama works that way, with night two in the Laguna Colorada Refuge, a shared dormitory with 2 to 6 beds and no heating on that night, and it reaches San Pedro at about 12:30 PM on day 3.

If altitude worries you, direction is one of the strongest levers you have, though the listings differ in price and length: $450 for 3 days from Uyuni against $332 for the 4-day round trip from San Pedro.

Arriving Through La Paz

Many travelers reach Uyuni from La Paz, and the altitude sources used for this guide give no elevation for La Paz itself, so do not assume it works as a low staging stop. The overnight bus is a 9-10 hour ride over about 569 km, departing around 9:00 PM and arriving early in the morning. Options run from $44 for the Todo Turismo Semicama Master Suite to $49 for the Cama Ejecutivo, with dinner and breakfast on board.

The BoA flight leaves La Paz at 07:10 and lands in Uyuni at 08:10, and since tours typically start around 10am, a same-day start is possible. That speed is the problem: it puts a full tour into your first hours at 3,665 m. Plan the connection with the La Paz to Uyuni guide and build at least one full Uyuni night into it.

Uyuni as the Staging Town

Uyuni town at 3,656-3,700 m is where you will sleep before almost any tour anyway, so treat those nights as the acclimatization they are. The CDC's extra-night rule is written for every 1,000 m of gain above 3,000 m, and night two of the lagoons route sits about 580-620 m above Uyuni town. Two nights in town before that route is in the spirit of that advice.

Travelers coming up from Argentina cross at Villazón and La Quiaca, where both towns already sit above 3,400 m, then continue by bus for 5-6 hours to Uyuni or by train in about 7-7.5 hours. Sucre is about 8 hours from Uyuni by bus over 229 km (142 miles), and Potosí about 4 hours over 148 km, but neither town's elevation is given in the sources here.

Day Tours as a Test

A one-day salar loop is a low-stakes way to learn how your body handles 3,663 m before committing to three days above 4,200 m. The Salar de Uyuni Tour 1 day with Sunset runs 9 hours, stays on the flat and ends back in Uyuni the same evening, so if you feel unwell you sleep at 3,656 m that night instead of at 4,278 m. That is a real safety valve.

Shared full-day loops run from $78 to $95 per person before the Incahuasi fee, a modest cost for what you learn about yourself.

Which Tours Carry Oxygen

Oxygen is named explicitly in only some listings. The 3-Day Tour to the Uyuni Salt Flat and Colored Lagoons includes an oxygen tank on the second night, the one at Laguna Colorada, at a $290 listed price or $352 with mandatory extras. The San Pedro de Atacama: 4-Day Uyuni Salt Flats Tour states that an oxygen bottle is included, priced at $332 for the 4-day, 3-night round trip.

The other lagoons listings do not mention oxygen in their inclusions, which is not the same as saying no driver carries a bottle, but it is not confirmed either. When you book, treat oxygen as an inclusion you verify rather than assume, and ask the operator directly before paying.

Coca Tea, Honestly

Coca leaf and coca-leaf tea are legal in Bolivia and are the traditional local remedy offered to newly arrived travelers against soroche, the local word for altitude sickness. The peer-reviewed evidence for it is thin: a review in the Tropical Diseases, Travel Medicine and Vaccines journal notes that no clinical trial evidence supports the practice. Drinking a warm cup is pleasant and harmless for most people, and it is offered everywhere in Uyuni.

Just do not mistake it for acclimatization, and note the legal point the same source raises: coca products become illegal narcotics under international law once carried out of the Andean coca-producing countries, so drink the tea in Bolivia and do not pack the leaves. The one exposure on this route that no drink changes is the cold at night.

Cold Nights Make Altitude Harder

Cold does not cause altitude sickness, but a freezing, sleepless night at 4,278 m will make any altitude symptom feel worse. The ERA5 climate archive gives June-August average nighttime lows of about -3.7°C to -4.0°C at Uyuni town, and the reserve's higher ground at 4,200-5,400 m runs colder on the same nights. The 3-Day Uyuni Salt Flats Tour ending in San Pedro de Atacama describes its second-night lodge as basic with no heating, with hot showers working about 75% of the time, and includes a sleeping bag from May to September for the winter nights.

On the Andes Salt Expeditions lagoons tour the sleeping bag rental is excluded from the $352 total. Warm layers are not optional on this route, and the season-by-season breakdown is in the best time to visit Uyuni guide. What to put in the bag is a separate question, answered in the Uyuni packing list.

The Geography of Descending

On day two of the lagoons route you are at Laguna Colorada at 4,278 m, and the next day's stops climb to the geysers near 4,900 m before dropping to Laguna Verde at 4,310 m or heading to the Hito Cajón pass at 4,480 m. The realistic descent is back north toward Uyuni at 3,656-3,700 m, a long jeep ride, or on into Chile once the border is crossed, with San Pedro town about 45 km from the pass. That asymmetry is why timing matters.

Symptoms that get worse rather than better overnight at 4,278 m are the point to tell the driver, before the next morning's climb toward 4,900 m. One listing already warns that the vehicle may stop briefly due to altitude, so drivers on this circuit expect the conversation.

Choosing a Route That Matches Your Body

The honest framing for the booking decision: if you have never slept above 3,000 m, or you have had altitude illness before, the 3-day lagoons route is the part of an Uyuni trip that carries the risk, not the salt flat. A day loop keeps you at about 3,663 m, ends in town, and still delivers the salt crust, the mirror in the wet months and Incahuasi when it is reachable. The lagoons, flamingos and geysers are the reward for a night at 4,278 m and a morning near 4,900 m, and they are covered in detail in the Laguna Colorada guide so you can weigh what you would be giving up.

To weigh the two side by side, compare one-day and three-day Uyuni tours by route and height. There is no shame in the one-day choice, and it is the safer trip for pregnancy, back problems and altitude risk alike, which is exactly what the tour listings themselves advise.