It is customary to consult the weather forecast daily in this modern information era. The forecast may indicate that the weather will be balmy and warm but not too hot. When you get to the beach, however, you begin to doubt the accuracy of the weather forecast as balmy and warm has become sizzling hot. It always seems hotter at the beach than further inland – why is this?
The sun feels hotter at the beach because the sand is warmed by the sun and radiates heat, adding to the temperature at the beach. The ocean water and sand also reflect some sun rays, which will increase the heat. Our subjective perceptions may make us think the beach is always being hot.
There are many perplexing questions related to the sun and how it warms the earth. We notice many of these details when we are on holiday visiting the beach.
Is It True That The Beach Is Hotter Than Other Areas?
When we spend time at the beach, we often get the impression that the beach is hotter than inland areas. You may think this is all in your head or wonder if it is an actual fact.
The beach is often warmer than inland areas because of its composition and geographical features. The fact that the beach has a higher temperature than other areas is usually only valid for the summer months.
The beach may be colder in winter than other areas due to the wind and the weaker sun’s rays. The wind is generally stronger at the beach. As winds are more prevalent in winter, they can lower the beach temperature through wind chill factors.
The Sand Makes A Beach Hotter
Specific heat capacity is the measure of energy needed to heat a kilogram of material by one degree. Sand has a relatively low SHC -specific heat capacity. The result is that sand quickly heats up when the sun’s rays strike the beach.
Sand is stationary and does not move around or evaporate like heated water would do. Water loses or disperses heat by the movement of particles within the water body or to the air in the form of water vapor. Since sand does not move around, the heat is retained in the sand, causing a significant increase.
When sunlight strikes the sand particles, energy is transferred to the sand. This causes the molecules to increase their vibration, which we perceive as heat when we touch the sand.
In some regions of the world, the sun is scorching, and the sand heats up rapidly. After three hours of sunshine, the sand will be twenty degrees hotter than the air. In some experiments, it was noted that the sand was double the air temperature. This explains why your feet burn when you walk on the beach.
It is useful to note that dark-colored beach sand will retain more heat than white sand. Black sand beaches are often popular tourist destinations, but they will be hot beaches in summer—for example, Lafayette Beach in Tahiti or Panalu’u Beach in Hawaii. Many ‘white’ beaches also have black sand grains, which increase heat absorption.
The heat retained in the sand warms the air in contact with the sand. This air rises and is replaced by cooler air which is warmed by the heat from the sand. In this way, hot beach sand adds to the temperature at the coast.
Does Light Reflection Play A Role In Heating Up The Beach?
To understand the role of reflection in heating beaches, we need to understand something about light physics.
Light is absorbed by materials, except for the color you perceive an object to be. For example, a red object absorbs the light rays but reflects the red light, which is why you perceive it as red. Black objects absorb all the available light, and white objects reflect all the light.
Most beaches are varying shades of off-white to yellowish-white. This indicates that the sand reflects a large proportion of the light that shines on it. Water in the ocean absorbs some of the light rays and reflects others.
We, therefore, have light rays being reflected from both the sea and the beach. Reflected rays carry heat, and as a result, when you go to the beach, you experience heat directly from the sun and from light reflected by the sand and water..
Limited Shade And Vegetation Increase Beach Temperatures
There are usually no trees on the beach, and apart from small beach umbrellas, there is no shade. The expanse of sand allows the temperature to increase as the sand and water reflect the light in all directions. The sun’s rays reach every area of the beach, and there is no shade to counteract the heat.
Vegetation does not absorb as much heat due to its water content. Plants offer some shade which further cools down the area. On the beach, there is seldom any vegetation. The bare sand heats up to searing levels without vegetation to cool the temperature.
Perceptions Of Heat Make The Beach Feel Hotter
Most people go to the beach in summer, and their time on the beach is spent in minimal clothing such as swimwear, shorts, and sleeveless shirts.
The fact that you might always go to the beach in summer and experience the heat will be stored in your memories. The association you have of the beach will be that it is always hot when in fact, there are months when it can be brisk and icy at the beach.
Wearing skimpy clothing exposes our skin to the sun’s rays, including ultra-violet rays that can burn our skin. When our skin burns, our body temperature goes up, and our brains automatically alert us to this fact to tell us to seek shade.
You will experience the beach as much hotter when you burn in the sun. The physiological memory reinforces your perception of the beach as very hot. You may feel cooler at the beach if you wear loose-fitting, light-colored clothing that covers more of your body.
Conclusion
The sun feels hotter at the beach during summer but not generally during winter. The sand absorbs and radiates the heat to increase the temperature at the beach. Reflected light rays from sand and water also increase our experience of the sun’s heat. In many people’s memories, the beach is associated with a scorching sun because they always visit it in summer. Burning our skin in the sun will intensify the memory of the beach being uncomfortably hot.
References
- https://temperaturemaster.com/does-sand-hold-heat/
- https://flexbooks.ck12.org/cbook/ck-12-middle-school-physical-science-flexbook-2.0/section/15.4/primary/lesson/specific-heat-ms-ps/
- https://www.scienceabc.com/nature/why-does-the-sun-reflect-off-seas-and-oceans.html
- https://www.scientificamerican.com/article/how-exactly-does-light-tr/
- https://spectrumnews1.com/ca/la-west/weather/2021/07/30/why-it-feels-so-hot-at-socal-beaches-when-the-forecast-calls-for-70s—
