JEDDAH: The appearance of the Suhail star in Saudi Arabia’s southern skies is traditionally seen as a sign that the most intense summer heat is beginning to ease and milder autumn conditions are approaching. The star’s appearance coincides with the Al-Tarfah period, which continues until Sept. 5 and is traditionally associated with warm days, milder nights and increased moisture over mountainous areas. According to the Saudi Press Agency, Mohammed Al-Wadai, a researcher specialising in the agricultural calendar, said Suhail is followed by a series of traditional astronomical periods associated with seasonal changes. Al-Jabhah, which runs from Sept. 6 to 18, is regarded as the effective start of autumn, with noticeably milder evenings. It is followed by Al-Zubrah from Sept. 19 to Oct. 1, when day and night become roughly equal in length and temperatures become cooler around dawn in mountainous areas. Al-Sarfah, from Oct. 2 to 14, traditionally marks the retreat of summer heat and the onset of milder conditions. Al-Wadai said the period is important for farmers in plains and mountain terraces, who begin preparing and fertilising land and planting winter vegetables and leafy crops as evaporation rates fall. Traditional sayings in southern Saudi Arabia also reflect generations of observations linked to the season. One saying, “When Suhail rises, the floods deepen,” refers to the increased likelihood of seasonal rainfall during this period. Moist air currents can contribute to cloud formation and rainfall over the highlands of Asir, Jazan and Al-Baha, while temperature differences between day and night can lead to morning fog. The conditions can help revive vegetation and increase soil moisture across plains and mountain terraces. Majed Al-Sahoubi, a specialist in astronomy and the relationship between stars, seasons and weather, previously told Arab News that the timing of Suhail’s appearance varies across the Kingdom. “It appears in Jazan in the south of the Kingdom around Aug. 7, in central Saudi Arabia around Aug. 24, and in the far north between approximately Sept. 7 and 10,” he said. Al-Sahoubi stressed that Suhail itself does not cause changes in temperature or rainfall. “Arabs have known and cherished Suhail since ancient times, but its appearance has no direct connection with rainfall,” he said. “Rather, it is associated with improving weather conditions. This relationship is indicative rather than causal. Suhail is a sign that conditions are beginning to improve, but the star itself does not influence or change the weather.” He said rainfall during the period was generally irregular across central Arabia and desert areas, while it tended to be more consistent in southern regions such as Abha and Al-Baha. “In desert areas, rainfall at this time of year is usually irregular, while a more consistent rainy period begins around Oct. 16, God willing,” he said.