September is one of the warmer months of the year in As Sulayyil, with average highs near 40.4°C and lows around 24.7°C (mean 32.6°C). It is about average for rainfall, averaging 1 mm of rainfall and 15% relative humidity across the period.
September is one of the warmer months of the year in As Sulayyil. Across 45 years of records, the warmest September in As Sulayyil was 2023 — when the month averaged 34.4°C — while the coldest was 1986 at 30.9°C. Typical September days reach 40.4°C with nights near 24.7°C. The long-term trend is warming, about 0.5°C per decade.
September is about average for rainfall in As Sulayyil, averaging 1 mm of rainfall. The wettest September on record was 1986 with 11 mm, while the driest were 2022, 2023 and 2025, among others at 0 mm.
Relative humidity in As Sulayyil during September averages 15%. The most humid September was 1999 at 20%, and the least humid was 1983 at 13%.
September receives about 6.9 kWh/m²/day of solar energy in As Sulayyil. The sunniest Septembers were 1997, 2005 and 2006 at 7.2 kWh/m²/day, and the cloudiest was 1988 at 6.3.
Average wind speed in As Sulayyil during September is 2.7 m/s. The windiest September was 2019 at 3.1 m/s, while the calmest was 1991 at 2.3 m/s.
Ranked against the other 11 months using 1981–2025 averages.
| Metric | 1980s | 1990s | 2000s | 2010s | 2020s | Change |
|---|---|---|---|---|---|---|
| Avg Temp | 31.7°C | 32.3°C | 32.5°C | 33.1°C | 33.5°C | +1.8°C |
| Avg High | 39.7°C | 40.1°C | 40.4°C | 40.8°C | 41.2°C | +1.5°C |
| Avg Low | 23.7°C | 24.4°C | 24.6°C | 25.3°C | 25.9°C | +2.2°C |
| Avg Rain | 2 mm | 0 mm | 0 mm | 0 mm | 1 mm | -1 mm |
September temperatures in As Sulayyil have risen by about 2.2°C between 1981–1985 and 2021–2025.
September has ranged from a record low of 19°C (1989) to a record high of 45.1°C (2018).
Rainfall in September is about average for rainfall, averaging 1 mm, with a wettest year of 11 mm.
A quieter season to visit As Sulayyil
If your dates are flexible, the more temperate months of November and February tend to be the most comfortable for visiting As Sulayyil. That said, September — with days averaging 40.4°C and nights around 24.7°C (mean 32.6°C) and low rainfall (1 mm) — can still be rewarding for travellers who don't mind the warmth, and often means fewer crowds.
| Year | Avg High | Avg Temp | Avg Low | Hottest Day | Coldest Day | Rainfall | Humidity | Wind | Solar |
|---|---|---|---|---|---|---|---|---|---|
| 2025 | 41.6°C | 34.1°C | 26.6°C | 44.6°C | 24.0°C | 0 mm | 18% | 2.9 m/s | 6.8 |
| 2024 | 41.7°C | 33.9°C | 26.2°C | 43.6°C | 23.9°C | 6 mm | 17% | 2.7 m/s | 6.9 |
| 2023 🔥 | 42.0°C | 34.4°C | 26.9°C | 43.8°C | 24.2°C | 0 mm | 15% | 2.7 m/s | 6.9 |
| 2022 | 40.8°C | 33.1°C | 25.4°C | 43.0°C | 21.2°C | 0 mm | 16% | 2.6 m/s | 6.9 |
| 2021 | 40.6°C | 32.8°C | 24.9°C | 43.4°C | 20.2°C | 0 mm | 14% | 3 m/s | 6.9 |
| 2020 | 40.3°C | 32.7°C | 25.1°C | 42.2°C | 22.4°C | 0 mm | 16% | 2.8 m/s | 7.1 |
| 2019 | 41.4°C | 34.0°C | 26.7°C | 44.9°C | 23.8°C | 0 mm | 18% | 3.1 m/s | 6.9 |
| 2018 | 41.7°C | 33.8°C | 25.8°C | 45.1°C | 22.7°C | 0 mm | 16% | 2.7 m/s | 7 |
| 2017 | 40.8°C | 33.0°C | 25.2°C | 43.2°C | 20.6°C | 0 mm | 14% | 2.5 m/s | 7.1 |
| 2016 | 40.8°C | 33.3°C | 25.7°C | 44.3°C | 22.1°C | 0 mm | 15% | 2.7 m/s | 6.9 |
| 2015 | 40.6°C | 32.9°C | 25.1°C | 44.5°C | 20.7°C | 0 mm | 15% | 2.8 m/s | 7 |
| 2014 | 40.5°C | 32.9°C | 25.3°C | 43.2°C | 21.3°C | 0 mm | 16% | 2.6 m/s | 6.8 |
| 2013 | 40.4°C | 32.7°C | 24.9°C | 43.2°C | 21.2°C | 0 mm | 15% | 2.5 m/s | 6.9 |
| 2012 | 40.4°C | 32.4°C | 24.3°C | 43.6°C | 21.5°C | 0 mm | 13% | 2.4 m/s | 7 |
| 2011 | 40.9°C | 33.2°C | 25.6°C | 43.3°C | 23.3°C | 0 mm | 15% | 2.6 m/s | 7 |
| 2010 | 40.5°C | 32.7°C | 24.8°C | 45.0°C | 20.3°C | 0 mm | 15% | 2.9 m/s | 7.1 |
| 2009 | 40.8°C | 32.9°C | 25.0°C | 44.2°C | 22.6°C | 0 mm | 14% | 2.8 m/s | 7 |
| 2008 | 40.9°C | 33.0°C | 25.1°C | 43.3°C | 22.4°C | 0 mm | 15% | 2.8 m/s | 6.9 |
| 2007 | 40.8°C | 32.8°C | 24.9°C | 44.2°C | 20.4°C | 0 mm | 14% | 2.8 m/s | 7 |
| 2006 | 40.4°C | 32.4°C | 24.4°C | 43.0°C | 20.8°C | 0 mm | 13% | 2.4 m/s | 7.2 |
| 2005 | 40.7°C | 32.7°C | 24.7°C | 43.7°C | 21.5°C | 0 mm | 14% | 2.6 m/s | 7.2 |
| 2004 | 40.2°C | 32.3°C | 24.3°C | 43.3°C | 20.2°C | 0 mm | 16% | 2.8 m/s | 7.1 |
| 2003 | 40.1°C | 32.2°C | 24.3°C | 43.5°C | 21.2°C | 0 mm | 15% | 2.7 m/s | 7.1 |
| 2002 | 40.6°C | 32.6°C | 24.7°C | 42.9°C | 21.7°C | 0 mm | 15% | 2.9 m/s | 7.1 |
| 2001 | 40.2°C | 32.2°C | 24.2°C | 43.0°C | 21.9°C | 0 mm | 15% | 2.9 m/s | 7.1 |
| 2000 | 39.7°C | 32.0°C | 24.4°C | 44.4°C | 22.1°C | 0 mm | 17% | 2.8 m/s | 6.9 |
| 1999 | 40.1°C | 32.4°C | 24.7°C | 42.7°C | 21.7°C | 0 mm | 20% | 2.6 m/s | 6.9 |
| 1998 | 41.3°C | 33.8°C | 26.2°C | 43.7°C | 23.2°C | 0 mm | 17% | 2.8 m/s | 7 |
| 1997 | 40.9°C | 32.8°C | 24.7°C | 42.6°C | 22.4°C | 0 mm | 14% | 2.7 m/s | 7.2 |
| 1996 | 39.8°C | 32.1°C | 24.4°C | 42.6°C | 20.0°C | 0 mm | 16% | 2.5 m/s | 6.7 |
| 1995 | 39.8°C | 31.8°C | 23.9°C | 42.1°C | 19.7°C | 0 mm | 15% | 2.5 m/s | 7 |
| 1994 | 39.8°C | 32.0°C | 24.3°C | 42.8°C | 19.8°C | 0 mm | 15% | 2.7 m/s | 6.5 |
| 1993 | 40.1°C | 32.1°C | 24.0°C | 43.2°C | 21.5°C | 0 mm | 14% | 2.8 m/s | 6.9 |
| 1992 | 39.1°C | 31.3°C | 23.5°C | 41.4°C | 20.8°C | 0 mm | 15% | 2.7 m/s | 6.6 |
| 1991 | 39.9°C | 31.9°C | 23.9°C | 42.4°C | 20.8°C | 0 mm | 15% | 2.3 m/s | 6.4 |
| 1990 | 40.5°C | 32.6°C | 24.7°C | 42.8°C | 21.5°C | 0 mm | 14% | 2.4 m/s | 6.6 |
| 1989 | 39.1°C | 31.3°C | 23.6°C | 42.0°C | 19.0°C | 0 mm | 16% | 2.6 m/s | 6.4 |
| 1988 | 40.2°C | 32.6°C | 25.0°C | 43.2°C | 20.6°C | 0 mm | 17% | 2.8 m/s | 6.3 |
| 1987 | 40.9°C | 32.7°C | 24.6°C | 43.7°C | 21.9°C | 0 mm | 15% | 2.9 m/s | 6.7 |
| 1986 ❄️ 🌧️ | 39.1°C | 30.9°C | 22.8°C | 41.3°C | 20.0°C | 11 mm | 17% | 2.5 m/s | 6.8 |
| 1985 | 39.9°C | 31.8°C | 23.7°C | 42.6°C | 19.6°C | 0 mm | 14% | 2.7 m/s | 7.1 |
| 1984 | 39.5°C | 31.4°C | 23.4°C | 41.9°C | 20.0°C | 0 mm | 15% | 2.7 m/s | 6.8 |
| 1983 | 39.8°C | 31.4°C | 23.1°C | 42.1°C | 21.0°C | 0 mm | 13% | 2.7 m/s | — |
| 1982 | 39.6°C | 31.6°C | 23.6°C | 42.7°C | 20.5°C | 5 mm | 16% | 2.7 m/s | — |
| 1981 | 39.6°C | 31.5°C | 23.4°C | 41.9°C | 21.1°C | 0 mm | 14% | 2.6 m/s | — |
Actual recorded September data for each year, 1981–2025 — sourced from NASA POWER.
The average high in September is around 40.4°C with lows near 24.7°C (mean 32.6°C), based on 45 years of NASA POWER data.
September averages 1 mm of rainfall in As Sulayyil, about average for rainfall. The wettest on record was 11 mm in 1986.
The hottest September reached 45.1°C in 2018. The coldest dipped to 19°C in 1989.
Comparing the earliest years on record (1981–1985) with the most recent (2021–2025), average September temperatures have risen by about 2.2°C. Daytime highs moved from 39.7°C to 41.3°C and overnight lows from 23.4°C to 26°C over the same span.
September is one of the warmer months of the year in As Sulayyil and about average for rainfall, so plan for around 40.4°C daytime highs and 24.7°C at night.
Not quite — September is the 9th coolest month in As Sulayyil, averaging 32.6°C.
For September in As Sulayyil, pack light, breathable clothing and sun protection, with typical highs of 40.4°C and lows of 24.7°C.
Relative humidity in September averages 15% — relatively dry.
Average wind speed in September is 2.7 m/s. The windiest September on record averaged 3.1 m/s (2019).
The wettest September on record was 1986 with 11 mm. On average, September sees 1 mm.
All figures are derived from NASA POWER (Prediction Of Worldwide Energy Resources), based on MERRA-2 satellite reanalysis, covering 1981–2025.
Explore how the weather in As Sulayyil behaves each September, based on 45 years of NASA POWER climate data from 1981 to 2025. This page breaks down average temperatures, rainfall, humidity, wind and solar radiation for September specifically, along with year-by-year records and how the month has changed over the decades.
