As September unfolds, the UAE experiences a significant seasonal transition. The autumnal equinox on September 23 signals the official end of summer and the start of autumn, bringing notable changes in temperature, wind patterns, humidity, and weather conditions. While the intense summer heat lingers early in the month, the gradual shift leads to cooler nights, occasional rain showers, and rising chances of fog and mist, especially in the eastern and mountainous regions.
The autumnal equinox and seasonal shift
September 23 marks a pivotal astronomical event—the autumnal equinox—when the sun aligns directly over the equator. This celestial moment officially ends the UAE’s summer season and ushers in autumn. The National Center of Meteorology (NCM) highlights that this change is more than symbolic; it brings a gradual adjustment in the country’s weather.During the first half of September, the heat remains intense. However, as the month progresses, temperatures start to fall, especially at night. This cooling trend is influenced by the weakening of the Indian monsoon depression. As the monsoon influence fades, desert thermal lows originating from central Arabia begin to dominate. These lows often generate fresh winds that may stir up dust, reducing visibility in some areas.Eastern parts of the UAE can expect cumulonimbus cloud formations, with occasional rainfall and thunder. This rain can sometimes extend inland, bringing varying precipitation intensities to internal regions, a phenomenon that residents and visitors should monitor closely.
Winds, humidity, and weather patterns
The transition to autumn also affects wind and humidity patterns. During late nights and early mornings, southeasterly winds prevail. As the day advances, these winds shift to northwesterly directions due to the natural land and sea breeze cycle.This circulation also causes a slight increase in relative humidity, averaging around 49% during September. The rise in humidity, particularly in the second half of the month, increases the likelihood of fog and mist across different parts of the UAE. Historical data underscores the impact of humidity on visibility; for instance, June 2014 recorded 14 foggy days and 12 misty days, illustrating how these conditions can affect daily life, especially early morning commutes.
Temperature and wind extremes: What the numbers say
September’s climate statistics provide valuable insights into the UAE’s typical weather. Average temperatures range between 32.3°C and 34.2°C, with mean daily highs reaching 38.5°C to 40.6°C. Nighttime temperatures, offering some relief from the daytime heat, generally range from 26.8°C to 29.3°C.Looking back, the highest temperature recorded during September was an extreme 51.1°C at Mukhariz in 2016, while the coolest night dipped to 16.5°C at Jabal Jais in 2015.Winds generally blow at an average speed of 11 km/h, but stronger gusts can occur. The most powerful wind gust recorded in September reached 109.3 km/h at Al Ain Airport in 2008. More recently, a gust of 92.2 km/h was recorded at Al Saa in 2023.Rainfall, although generally scarce in this dry region, can occasionally be significant. The highest rainfall recorded in September was 86.4 mm at Jabal Hafeet in 2006.
Practical implications: What to expect and plan for
As September progresses, nights become more comfortable, inviting outdoor activities such as sunset walks, al fresco dining, and stargazing in desert areas. Mornings may present patchy fog, reducing visibility and potentially slowing down early commutes, especially on rural or less illuminated roads.Residents and visitors in the eastern UAE should remain alert for sporadic rain showers, which may also affect mountain areas. Planning ahead by checking weather forecasts is advisable before embarking on hikes or long drives.In summary, September serves as the UAE’s transitional month, gently moving the country from the peak heat of summer into the cooler, more temperate days of autumn. The shifting winds, rising humidity, cooler nights, and occasional rain showers all signal the start of a new season and a welcome change in weather conditions.
