Altitude in San Pedro de Atacama

This is the practical question that decides whether an Atacama trip is enjoyable, and it is almost always presented as a medical one. It is not. It is a scheduling one.

The numbers

Where	Elevation
Calama, where you land	2,260 m
San Pedro de Atacama, where you sleep	2,407 m
Valle de la Luna	about 2,600 m
Laguna Cejar and the salar	about 2,300 m
Valle del Arcoíris	about 3,100 m
Lagunas Miscanti and Miñiques	4,140 m
El Tatio geysers	4,320 m
The Bolivian altiplano, on the Uyuni crossing	over 4,900 m

San Pedro itself is only just above the threshold where altitude begins to affect people. The excursions are a different matter: El Tatio is nearly two kilometres higher than your bed, reached before dawn, after a ninety-minute drive.

What the tours themselves say

Worth quoting, because operators rarely volunteer anything that might reduce a booking.

The El Tatio operator writes: “We recommend taking other low-altitude tours before this tour, so you can acclimatize and avoid altitude sickness.”

The full-day Piedras Rojas operator lists who should not come at all: pregnant travellers, people with back problems, people with hypertension, anyone with a serious health condition, children under 7 and adults over 70 — on altitude grounds specifically.

When the people selling the tour tell you to do something else first, that is the strongest available evidence.

The order that works

This is the whole of the advice on this page, and it is free.

Day one. Arrive, get to San Pedro, do nothing demanding. Drink more water than you want to. If you arrive early enough, Valle de la Luna in the afternoon is about as much as is sensible, and it is at town height.

Day two. Low excursions. The salt lagoons at around 2,300 m, sandboarding at 2,500 m, or Valle de la Luna if you did not do it on arrival. None of these is higher than the town.

Day three. Now the high ones. El Tatio at 4,320 m, or the altiplanic lagoons at 4,140 m. Your body has had two nights at 2,400 m and the difference is substantial.

Day four and beyond. The second high day, Rainbow Valley, or the start of the Uyuni crossing — which sleeps above 4,000 m for two nights and should never be the first thing you do.

Most people get this exactly backwards, because El Tatio is the famous one and they book it for their first full day.

What it feels like

Headache, shortness of breath on mild exertion, poor sleep, loss of appetite, mild nausea. It typically starts some hours after you go up rather than immediately, which is why a 4 a.m. departure can feel fine and then not.

Fitness does not protect you. Neither does being young. Whether you get it is largely individual and mostly not under your control — but how fast you ascend is, and that is the part this page is about.

Practical things that help

Drink considerably more water than usual; humidity here runs between 13 and 38 per cent, so you lose water breathing without noticing. Go easy on alcohol for the first day or two. Eat lightly. Walk slowly — everyone new to San Pedro walks the streets too fast and arrives at the plaza out of breath.

Coca tea is offered everywhere and is part of local practice. Whether it helps is not well established, and it is not a substitute for ascending slowly.

Where this page stops

People search for Diamox dosing, whether ibuprofen prevents altitude sickness, and what not to eat at altitude. Those are medical questions and this is an affiliate travel site. We are not going to answer them, and any site that does without knowing your history is doing something it should not.

Speak to a travel clinic or your own doctor before you go, particularly if you have heart or lung conditions, high blood pressure, or are pregnant. If symptoms are severe — confusion, breathlessness at rest, a cough — the answer at any altitude is to descend, and in San Pedro that means getting to Calama.

Then plan the days in the right order, and book the low ones first.