DUBAI //Just before sunrise today a bright light in the night sky will signal the end of the summer heat and a return to more moderate weather.
At least, that is what the star of Suhail used to mean, before global climate change became involved.
Visible due south in the early hours before sunrise, Suhail, also known as Canopus, is the second brightest star in the sky after Sirius, and has always held a great significance to the people of the Middle East.
"Suhail's appearance means the beginning of the end of summer: the days begin to get shorter and temperatures begin to decrease," explained Rashad Bukhash, the director of the architectural heritage department at Dubai Municipality.
"Back in the day, many people used to say the water in their wells was hot the day before Suhail appeared and cool the next day."
But do not turn your hot water tanks back on just yet, because tracking of the star by a local astronomer over the past seven years seems to suggest global warming has taken away its twinkle.
Hasan Al Hariri, chief executive of the Dubai Astronomy Group, has been monitoring Suhail's rise since 2004 - specifically because the rise marks the start of the farmer's agricultural, or droror, calendar.
The droror agricultural calendar begins with the sighting of Suhail and is then measured in 10 or 13-day micro-seasons known as dir.
Between 70 and 80 days after Suhail appears, camel grazing, studding and palm pollination can commence.
"It is not as accurate as it was in the old times due to global changes in the weather," said Mr Al Hariri, who described the change as "huge and unbelievable".
A common joke among elders these days, he said, is: "Did your calendar work this year?"
"We are joking with each other, but also trying to observe the difference and see how it can be compensated for," Mr Al Hariri said.
"We're trying to make the system survive but it isn't surviving."
If meteorologists' predictions are right, Mr Al Hariri and the farmers are in for more disappointment this year: temperatures are expected to remain in the mid-40s for at least the next two weeks.
"Most of people who use the calendar system have died," admitted Mr Al Hariri. But he and those who remember the tradition want very much to find a way to keep it alive.
The star, which appears every year about this time and stays visible in the night sky until May, has been observed by populations dating as far back as the Ancient Egyptians.
The appearance of Suhail also traditionally marks the start of the hunting season, Mr Bukhash said, because hunters in those days had to endure days of travelling through the desert.
"Suhail is very often mentioned in Arab poetry, stories, and Bedouin sayings. Many people considered it to have healing powers. Since the weather improves when the star is in the sky, people feel healthier and so they attributed it to the star," added Mr Bukhash.
Despite the star's popularity and significance in the east, it remains obscure in western culture. This, presumably, because it was not visible to the Romans or the Ancient Greeks.
The northern limit of visibility for the star is latitude 37°18' north, which is just south of cities like Athens and San Francisco.
"It was considered good luck by pearl divers and many travellers used it for navigation as well as finding the direction of Mecca so they could pray," said Mr Bukhash.
Suhail is still used in navigation today. Its brightness and location make it popular for space navigation. Many spacecrafts, including those used by Nasa, carry a special camera known as a Canopus Star Tracker.