Field Notes · Sand
Why the desert is a night place
Deserts are photographed at noon and lived at night. The temperature drop after sunset, the sky without light pollution and the dawn walk are the desert’s real hours, and a plan that respects them is a different trip.
The photograph of a desert is taken at midday because that is when the photographer was awake, and it shows the desert at its least interesting: flat light, no shadow, heat haze. The desert itself keeps different hours. It starts at the first grey light, when the sand is cool enough to climb and the dunes carry the long shadows that give them their shape. It stops around ten. It starts again at four, when the light goes gold, and it becomes extraordinary after dark, when the temperature falls twenty degrees and the sky comes down to the ground.
The swing
Dry air does not hold heat. In humid places the night stays warm because the water in the air acts as a blanket; in a desert there is no blanket and the heat leaves as soon as the sun does. The Climate Simulator shows the numbers: Wadi Rum in April goes from 26 by day to 11 by night, the Namib in July from 23 to 5, the Atacama in June from 19 to minus 2. The practical result is that a desert trip packs for two seasons at once, and the down jacket that seems absurd at the airport is the item you are most grateful for at four in the morning.
The plan that works
Walk at dawn. The dune at Sossusvlei, the saddle behind the camp in Wadi Rum, the first hour on the salt: these happen between first light and about nine, and the fit are back at the vehicle before the sand burns through the shoe. Drive or rest through the middle of the day; nothing you can see at noon is worth what it costs to see it. Move again at four. Sit outside after dark, and if the camp offers a mattress outside the tent, take it.
The Daylight Simulator gives the exact times, and they are earlier than city habits expect. Sunrise in Wadi Rum in April is a little after six; in the Namib in July it is nearly half past seven, which is why the park gate opens with the light and the drive to the pan is done in the dark.
Water as a number
Thirst is a late signal in dry air because the sweat evaporates before you notice it. The rule on every desert page here is three litres a person on a walking day in comfortable temperatures and up to five above thirty degrees, drunk before thirst rather than after. The frozen bottles that the villages sell at the edge of the Danakil are the best money on that trip: they are cold water at two in the afternoon, when everything else is warm. The Pack Simulator counts water at a kilogram a litre, which is why desert walking days are short and the vehicle carries the rest.
The night
All three deserts on this site are dark-sky places; the Atacama is the darkest inhabited place on earth by most measures, which is why the world’s big telescopes sit on the ridges above it. A moonless night is the thing to book around: the Milky Way is a shadow-casting object in the Atacama and the Namib, and the full moon erases it. It is the hour the photographs never show and the reason people go back.
Questions people ask
How cold does a desert night get?
The swing between day and night is twenty degrees or more in dry air. Wadi Rum in winter goes from 15 to 2; the Atacama in June from 19 to minus 2; the Namib in July from 23 to 5. A summer sleeping bag is not enough anywhere on this list in the cool months.
How much water?
Three litres a person on a walking day in the mid twenties, four to five above thirty degrees. On a vehicle day, two. The Pack Simulator counts it as weight, which explains why desert walking days are short.
