Why does the desert get cold at night? You may have wondered why they get so cold at night even though they are known for their scorching heat.
During the day, the desert temperature can go as high as 38C. But, it can fall to an average of – 3.9 at night.
Because of these fluctuations, it is natural to ask, why does it get so cold at night in the desert?
Yes, it has to do with how the desert landscape absorbs and releases heat. But, is there any specific answer to, “Why do deserts get cold at night?”
The reason for temperature fluctuations in the desert is mainly the low humidity in the air, which causes quick heating during the day and quick cooling at night.
How is Desert Climate Different from the Rest?
The characteristics of desert climates are different from those of other climates because they are very dry and experience significant changes in temperature.
Here are some distinguishing features that set desert climates apart:
Low Precipitation
Deserts are characterized by low precipitation, meaning they typically receive less than 250 mm of rainfall annually.
The absence of water causes a dry and barren atmosphere, which is different from the damp and moist surroundings of other climates like tropical or temperate regions.
High Evaporation Rates
Deserts experience high evaporation rates because of the combination of intense sunlight and high temperatures, which causes water to evaporate more quickly than in other climates.
The statement implies that due to the quick evaporation of even the slightest amount of water in the surroundings, the landscape becomes even more arid.
Extreme Temperature Changes
Deserts have extreme temperature changes where the temperature is very hot during the day and very cold at night.
On the other hand, some climates experience milder temperature variations, where the difference between daytime and nighttime temperatures is not as noticeable.
Limited Vegetation
In desert climates, water scarcity and dry conditions result in limited vegetation growth. In the desert, there are only a few plants that can survive due to the harsh conditions.
These plants are specially adapted to the environment and include cacti and succulents.
Why Does the Desert Get Cold at Night?
Deserts are characterized by their harsh climate, which includes extremely high temperatures during the day and very low temperatures at night.
What is the reason behind the sudden and significant changes in temperature?
Well, many different factors are at play here:
Lack of Moisture
The desert experiences cold temperatures at night primarily due to the absence of moisture present in the air.
Deserts are areas that have dry climates with very little precipitation and low levels of moisture in the air.
During the day, the lack of moisture in the air makes it easier for the sun’s rays to reach the Earth’s surface, leading to a rapid temperature increase.
The absence of moisture in the air can cause heat to dissipate rapidly during the night, resulting in a significant decrease in temperature.
An Important Consideration
The presence of water vapor in the atmosphere has a natural insulating effect, which helps to keep the heat close to the Earth’s surface.
Fact: In places with high humidity, the trapped heat helps maintain consistent temperatures during both day and night.
Clear Skies
In general, desert regions usually have few clouds and mostly clear skies.
Clouds have the ability to regulate temperature by reflecting some of the sun’s rays during the day and trapping heat near the Earth’s surface at night.
The absence of clouds in the desert allows the sun’s rays to pass through during the day and escape at night, resulting in extreme temperatures.
Low Specific Heat Capacity of Sand and Rocks
The amount of heat a substance can absorb before its temperature increases is measured by its specific heat capacity.
Substances like water with a high specific heat capacity can absorb a large amount of heat energy without undergoing a significant increase in temperature.
Materials with a low specific heat capacity, such as sand and rocks, have the ability to quickly absorb and release heat, resulting in rapid heating and cooling.
An Important Consideration
Desert environments have a low specific heat capacity for the sand and rocks that make up the Earth’s surface.
This means that they heat up quickly during the day but also cool down rapidly once the sun sets.
The reason why deserts experience a sudden decrease in temperature during the night is due to the quick loss of heat.
Fact: The term "diurnal temperature range" means the variation in temperature between the highest temperature during the day and the lowest temperature at night.
Radiative Cooling
Radiative cooling refers to the method in which an object releases heat by emitting infrared radiation.
The process is highly efficient in desert regions due to the absence of cloud cover and dry air that facilitates the rapid dissipation of heat into the atmosphere.
The Earth’s surface and any objects on it absorb energy from the sun’s rays during the day, which causes them to heat up.
When it gets dark and the sun goes down, these things start to release heat through radiative cooling. This results in a sharp drop in temperature.
Elevation
Nighttime cooling in certain deserts can be influenced by altitude. Higher elevations are cooler because the atmosphere is thinner and the air pressure is reduced.
Sometimes, cooler air can get stuck under a layer of warmer air, which is called a temperature inversion. This can make the nighttime cooling effect even stronger.
Temperature Inversion
When the usual pattern of decreasing air temperature with increasing altitude is reversed, it is called a temperature inversion.
In desert environments, a phenomenon can occur where the ground cools rapidly, particularly during the night.
The ground releases heat which causes the air closest to the surface to cool down faster than the air above it.
A layer of colder air is formed under a layer of warmer air, which stops heat from escaping upwards and strengthens the nighttime cooling effect.
Wind and Air Circulation
At night, wind can cause desert environments to cool down quickly. The Earth’s surface gets heated by the sun during the day, which results in the air above it expanding and rising.
The process described causes the formation of regions with reduced atmospheric pressure close to the surface.
This phenomenon can result in the influx of colder air from neighboring regions.
Localized winds can form at night due to the cooling of the ground and the air above it. This can cause the temperature to decrease even more.
An Important Consideration
The winds that occur at night are known as drainage winds or katabatic winds.
They move from higher elevations to lower elevations and carry colder air along with them.
When cold air moves over the desert, it can make the temperature drop even more quickly because it speeds up the cooling process.
Deserts Getting Cold at Night and the Adaptation of Desert Life
Plants and animals that live in the desert have developed different ways to deal with very hot days and very cold nights.
These adaptations help them survive in this harsh environment.
Desert Plants Adaptations
Some desert plants slow down their metabolic processes during cold nights to conserve energy and reduce water loss through transpiration.
Some plants in the desert have a covering of fine hairs or fuzz on their leaves or stem.
The insulation helps to safeguard the plant from cold temperatures during the night by trapping a layer of air around it.
Some desert plants, like the ocotillo and different types of cacti, perform their photosynthesis and other metabolic activities at night when the temperature is lower.
This helps them save water and energy.
Fact: Certain desert plants, such as the barrel cactus, have a thick and fleshy structure that can retain heat during the day.
Desert Animals Adaptations
Many animals living in the desert have developed a behavioral adaptation to cope with cold desert nights.
They have become nocturnal, which means they are active during the night when the temperatures are cooler.
During the hot part of the day, animals conserve energy and water and wait until it is cooler to search for food and water.
Desert animals like the fennec fox have developed a way to keep themselves warm during cold nights by growing thick fur or feathers that act as insulation for their bodies.
The insulation layer helps to keep the warm air close to the body, which in turn helps to regulate the body temperature.
Fact: Burrowing is a survival strategy used by certain desert animals like rodents and reptiles, to protect themselves from the cold temperatures during the night.
Takeaway
Why does the desert get cold at night? Many factors are at play here but the deserts usually get cold at night because of their climate characteristics and unique landscape.
Similarly, the absence of cloud cover, a lack of moisture, and the desert’s sandy surface also contribute to low nighttime temperatures.
So, next time you are on a desert safari, be sure to pack some warm clothes because the nights are going to be quite chilly.
