Summer heat in Dubai
Summer in Dubai Image Credit: GN Archives

Dubai: Summer officially begins tomorrow in the UAE, as the summer solstice or the longest day of the year falls on June 21, this year.

What is a solstice?

The word solstice is derived from two Latin words: sol (the Sun) and sistere (to be still). Twice each year, the Earth's axis is tilted most closely toward the Sun. During this time, the hemisphere tilted closest towards the Sun sees its longest day, while the hemisphere tilted away from the Sun sees its longest night. The Northern Hemisphere’s summer solstice always falls around June 21.

According to the National Center of Meteorology: "The summer solstice occurs when the Sun’s rays are directly over the tropic of cancer (23.37 degrees North) and the country experiences the longest day of the year."

Increase in temperatures?

But, does this mean a sudden and drastic increase in temperatures? Not exactly. Speaking to Gulf News, Dr. Ahmed Habib, a National Centre of Meteorology official, explained: "Yes, it's the longest day of the year tomorrow and summer begins tomorrow officially, but the temperatures are already high. There is no significant increase expected."

He further added that temperatures around this time, in June, are typically around 47-49°C, going to 50°C on some days. The NCM data shows that the mean temperatures across the country increased by approximately two to three degrees Celsius higher in June as compared to May.

100 per cent humidity: Feeling hotter than it really is?

Dr. Habib explained that it is normal for UAE to record high humidity during the month of June, especially in the coastal parts of the country.

Explained: What is heat index and how it affects the human body’s comfort

He said: "For example, today (June 20), we recorded 100 per cent humidity in some coastal areas. This is not unusual, the level of humidity depends on the direction of the air mass. If the air mass is coming from the sea, the humidity will be high. If it is coming from the southeast or southwest parts of the country, the air mass will be arid."

Since the afternoon temperatures are already high across the UAE, the heat index or the “feeling temperature” might be higher depending on weather conditions such as the humidity.

He said: “When the air temperature is extremely high, if the relative humidity is also very high, we might feel like the temperature outdoors is much higher than the actual reading.”

Sunrise and sunset

Summer solstice means that in terms of daylight, UAE will now see longer days in the coming weeks as compared to the previous month. Days will get shorter during the winter months. Tomorrow sunrise will be at 5:35am and sunset will be at 7:14pm.