UAE braces for high humidity as 'sweat-tember' arrives

Shift in winds set to increase humidity in coastal areas, National Centre of Meteorology predicts

View of the hot and humid weather in Dubai. Pawan Singh / The National

Residents across the UAE have been experiencing more pleasant mornings and evenings without high humidity, but this is forecast to change.

On Tuesday, the National Centre of Meteorology said humidity levels were set to increase over the next five days, especially on the coast.

The change stems from a shift in the winds affecting the UAE, which are set to move from southerly winds that move in over land to the north-west.

“The north-west winds move over the sea bringing more water vapour towards the coastal areas, so the humidity will increase during the early morning and late night over coastal areas,” a forecaster at the NCM told The National. “The increase will be gradual over the next few days."

Humidity levels could rise to as much as 95 per cent over the coast in the early morning and evening but less so in internal parts of the country. The forecaster added that temperatures are expected to stay broadly the same with a maximum of about 42ºC on the coast and internally of about 46ºC. But bouts of fog are expected along with the increased humidity.

“This [type of weather] is normal for the middle of September,” the forecaster said. “Temperatures are coming down gradually.”

In the NCM’s five-day forecast, it said it would be partly cloudy at times, with a probability of some convective clouds forming in the east with a chance of light rainfall. Conditions are predicted to be similar into Wednesday with further humidity expected in the evening and Thursday morning over some coastal and internal areas with a probability of fog or mist formation.

“Clouds will appear eastward by afternoon,” the forecast for Wednesday read. “[It will be] humid by night and Thursday morning over some coastal and internal areas with a probability of fog or mist formation.”

Last month of summer

While September is traditionally a hot and humid month – often called “Sweat-tember” – the good news is that it is considered the last month of summer. The NCM said the Autumn Equinox falls on September 22 this year, meaning the sun is directly perpendicular to the equator and then moves south.

It marks the start of autumn in the Northern Hemisphere and is accompanied by a slow, steady decline in temperatures, especially at night. It comes after the sighting of the Suhail Star last month, which has traditionally signalled the days of intense, scorching heat are ending.

Ibrahim Al Jarwan, board chairman of the Emirates Astronomical Society and a member of the Arab Union for Astronomy and Space Sciences, told state news agency Wam this month that temperatures will begin to fall below 25°C at night and below 40°C during the day from the date of the autumn equinox.

Mr Al Jarwan said early autumn evenings will showcase several notable star constellations, including the “Big Dipper”, and the “Great Square of Pegasus”, referred to regionally as the “Aquarius Square” and they will begin to appear in the eastern sky.

Ancient Gulf calendar shows the way

The arrival and effects of the Autumn Equinox have also been highlighted in Al Durour, the ancient Gulf calendar. Believed to have been used for centuries years by people of the region, it was once well known among Emiratis and Gulf citizens.

Some experts said climate change has made it less reliable but it was used to forecast weather and also when to plant, fish and dive for pearls.