Every year there are about 30 days when sun protection becomes more of a necessity than an option. During that time, the temperatures are so high that you want to spend the day on the beach or hiking in the mountains, of course, always bringing sun protection, since otherwise you could end up with burns.

This season is known as Canicula, and runs between July 15 and August 15. But where does the name come from? And why is it the hottest time of the year?

Canicula history


The star Sirius (on the left).

Several thousand years ago, specifically 5.300, the hottest season of the year coincided with the celiac rise of the constellation Canis Major, and also with the rise of the star Sirius. But the truth is that nowadays this is not the case. In fact, due to the precession of the Earth's axis, Sirius appears as the brightest star in early September, while the hottest period begins on June 21.

Where does the name come from?

The term comes from can o canis in Latin it means 'dog'. It refers to the constellation Canis Major, since the star Sirius (also known as "The Scorcher" was the brightest in the night sky during the hottest time in the Northern Hemisphere. Even the expression "a dog's day ago" could be related to this term.

Why is the canicular period the hottest?

We might think that the hottest period of the year begins on June 21 in the Northern Hemisphere and on December 21 in the Southern Hemisphere, with the summer solstice, but the reality is that it is not. Why? By various factors: the own inclination and rotation of the planet earth, the solar radiation and the effect of the seas.

The planet, as we know, in addition to turning on itself, also tilts slightly. With the summer solstice, the sun's rays reach us straighter, more directly, but the sea continues to be still warm; Furthermore, the earth has only just begun to absorb the heat. For this reason, for a few weeks you can be quite well outside, since the sea refreshes the atmosphere. But this does not last long. By July 15 or so, the ocean water will have warmed enough to kick off 30 days of intense heat.

In areas where the climate is continental, the effect is less pronounced, so the maximum temperatures rise earlier. On the contrary, in places with temperate climates, especially in coastal areas, it is quite felt.

Is heat wave the same as heat wave?


Being the hottest season, we could call it a heat wave ... but this would not be entirely correct. The heat wave refers to 30 days during which the sun is more intense, but heat waves are meteorological phenomena characterized by the following:

  • Higher minimum and maximum temperatures exceed the averages recorded in the area for the date in question. It will depend on the area whether the temperature is considered "normal" or "extraordinary". For example, in cities like Córdoba a value of 37ºC in August is considered normal, but in Valladolid one could speak of a heat wave.
  • A duration of at least 4 days. Temperatures must remain higher than average for a few days, because in one day the human body hardly notices the effects of heat; On the other hand, if it is a lasting phenomenon, the houses, the asphalt, everything overheats, causing us to have to change our routine or habits until it passes.
  • Heat waves affect several provinces, at the very least. When very high temperatures are registered in a single city, there is no mention that a heat wave has occurred there, because for this to happen it should have affected other cities and towns as well. The wave of 2003 was especially hard precisely because of the extent it had, since it affected practically all of Europe. In Denia, for example, on August 2 they had 47,8ºC.
  • Regrettably, these phenomena can cause the death of people more delicate, such as children or the elderly. For example, following the wave of 2003, a total of 14.802 people died throughout the continent, which represented 55% more.

Thus, heat wave episodes do appear during the period known as heatwave, but they do not occur every year (these are increasingly rare, due to global warming).

How to cope with the heat

Summer in the countryside

High temperatures, especially when they exceed 30ºC, will force us to take some measures to continue with our day to day. The best way to cope is drinking a lot of water (minimum 2l / day), eat light, fresh food (like salads and fruits for example), and keep both the home and workplace ventilated.

Have you heard of heatwave?

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  1.   reviewer said

    «We could think that the hottest period of the year begins on June 21 (…)«: thinking about it, we could think that the hottest day is June 21, as it is the longest day, and from there it goes down the temperatures being the shortest days. Although as you have explained, this is not so. The same happens on December 21, which despite being the day with less sunlight (in the northern hemisphere), is when winter begins and it is not usually as cold as in January, when the days are longer.