Why Do Deserts Get Cold At Night?

Gobi Desert, Mongolia.

One might ponder the intriguing transformation of a desert from scorching hot during the day to surprisingly cold at night. Although deserts are renowned for their intense daytime heat, a lesser-known fact is their propensity to undergo substantial nocturnal temperature plunges, frequently catching people off guard. The arid nature of deserts, marked by minimal humidity, prevents the heat absorbed by the sun-baked sand throughout the sunlit hours from being trapped within the atmosphere. This distinctive phenomenon curtails heat retention, prompting the rapid dissipation of warmth and culminating in a swift reduction of the desert’s temperature during the nighttime hours.

Sand’s Ability to Heat the Air

Sand proves to be a true substance. Despite its arid nature, it possesses the intriguing paradox of being both dry and slippery. Its granules, which are larger in comparison to various soil types, contribute to its limited proficiency in water absorption. Furthermore, sand exhibits a modest aptitude for heat absorption, which is a crucial factor in the scorching temperatures experienced in deserts during the day.

When the sun’s fervent rays bathe the desert landscape, the sand doesn’t swiftly assimilate the incoming heat. Instead, it behaves akin to a mirror, adeptly reflecting and channeling the thermal energy upward toward the surrounding air. In contrast, terrains such as forests, beaches, plains, and mountains diverge in this regard; they do not redirect all the absorbed heat towards the air. Instead, they retain a portion of this thermal energy, absorbing it into their own structures.

With this understanding of the daytime desert heat established, let’s delve into the rationale behind the drastic nighttime cold that befalls these arid regions.

The Effect of Desert Air on Humidity

Water exhibits remarkable prowess in capturing and retaining heat. In the typical tapestry of landscapes, as the sun’s warmth bathes the earth, the soil dutifully absorbs a significant portion of this thermal energy. During the nocturnal hours, in the absence of the sun’s radiant influence, the heat emanating from the earth finds itself ensnared in the air just above the ground, thanks to the moisture content, or humidity, present in the atmosphere.

However, the narrative undergoes a significant shift within the arid expanses of deserts.

As the sun descends and the earth commences its release of heat through radiant processes, the air enveloping the desert terrain struggles to effectively clasp onto this warmth. This predicament stems from the scarcity of moisture within the air, impairing its capacity to retain heat. Consequently, this released heat dissipates with remarkable celerity, orchestrating a striking plummet in temperature during the night.

Furthermore, deserts typically exhibit scanty cloud cover, predominantly due to the exceptionally low humidity levels. This lack of cloudiness compounds the challenge of heat retention just above the ground. The heat, which ascends from the earth’s surface, finds an easy escape route into the cosmos, leaving behind a severe and unforgiving chill.

Not All Deserts Cool at Night

Undoubtedly, the nighttime cooling process within deserts is subject to a symphony of influences, encompassing variables such as humidity, cloud cover, and even the caress of the wind. It’s important to acknowledge that nature is replete with exceptions that defy conventional wisdom.

In direct opposition to the prevailing notion, not all deserts stand as stark, barren wastelands devoid of moisture. Nature, in its intricate design, always harbors deviations from the norm.

Regions like Kuwait and the UAE, akin to certain segments of the Sahara Desert, stand as testaments to this divergence. These particular desert realms, while still arid, embrace a relatively higher level of humidity when juxtaposed with their desert counterparts. Consequently, the veil of night doesn’t enshroud these landscapes in an equally extreme cold, for the air, imbued with humidity, captures a portion of the earth’s radiant heat. This retention of warmth within the humid air tempers the nocturnal temperature drop, offering a glimpse into the nuanced interplay of climatic dynamics within these distinct desert pockets.

Not All Deserts Are Dry, But Not All Are Hot

Adelie Penguin (Pygoscelis Adeliae).
Adelie Penguin (Pygoscelis Adeliae).

When the word ‘desert’ unfurls in our minds, it often conjures an expanse of land cloaked in sand. Yet, allow us to broaden this perception, for the image above challenges such preconceived notions. Behold, the scene captured in this picture is none other than a desert as well. Yes, these charming penguins inhabit what is known as a Polar desert.

This is the defining feature of a desert—meager precipitation levels, including rain as well as other manifestations like snow or sleet. By this very delineation, the icy expanse of Antarctica, shrouded beneath a mantle of frozen magnificence and subject to temperatures plunging to depths as extreme as -89.2°C (-128.6°F), assumes the identity of a desert. Despite its frozen veneer, this pristine continent bears witness to scarce instances of snow and rain throughout the year. As a testament to this arid reality, Antarctica emerges as one of the planet’s most extensive and parched deserts, etching its name into the annals of our world’s geographical wonders.