September is one of the warmer months of the year in Riyadh, with average highs near 40.5°C and lows around 24.7°C (mean 32.6°C). It is about average for rainfall, averaging 0 mm of rainfall and 15% relative humidity across the period.
September is one of the warmer months of the year in Riyadh. Across 45 years of records, the warmest September in Riyadh was 2018 — when the month averaged 34.7°C — while the coldest was 1983 at 31.3°C. Typical September days reach 40.5°C with nights near 24.7°C. The long-term trend is warming, about 0.4°C per decade.
September is about average for rainfall in Riyadh, averaging 0 mm of rainfall. The wettest September on record was 1982 with 1 mm, while the driest were 2023, 2024 and 2025, among others at 0 mm.
Relative humidity in Riyadh during September averages 15%. The most humid September was 1994 at 19%, and the least humid were 1983 and 1990 at 13%.
September receives about 6.7 kWh/m²/day of solar energy in Riyadh. The sunniest Septembers were 2004, 2005 and 2006 at 7 kWh/m²/day, and the cloudiest were 1988, 1989 and 1991 at 6.2.
Average wind speed in Riyadh during September is 2.5 m/s. The windiest September was 2021 at 3.1 m/s, while the calmest was 2008 at 2.1 m/s.
Ranked against the other 11 months using 1981–2025 averages.
| Metric | 1980s | 1990s | 2000s | 2010s | 2020s | Change |
|---|---|---|---|---|---|---|
| Avg Temp | 31.9°C | 32.3°C | 32.4°C | 33.1°C | 33.4°C | +1.5°C |
| Avg High | 40.0°C | 40.2°C | 40.4°C | 40.9°C | 41.1°C | +1.1°C |
| Avg Low | 23.8°C | 24.4°C | 24.5°C | 25.4°C | 25.6°C | +1.8°C |
| Avg Rain | 0 mm | 0 mm | 0 mm | 0 mm | 0 mm | 0 mm |
September temperatures in Riyadh have risen by about 1.6°C between 1981–1985 and 2021–2025.
September has ranged from a record low of 18°C (1989) to a record high of 45.5°C (2018).
Rainfall in September is about average for rainfall, averaging 0 mm, with a wettest year of 1 mm.
Daytime highs and overnight lows have shifted differently — highs rose about 0.3°C per decade while lows rose 0.5°C per decade, narrowing the gap between day and night.
A quieter season to visit Riyadh
If your dates are flexible, the more temperate months of November and March tend to be the most comfortable for visiting Riyadh. That said, September — with days averaging 40.5°C and nights around 24.7°C (mean 32.6°C) and low rainfall (0 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 | 41.5°C | 33.7°C | 25.8°C | 43.9°C | 23.2°C | 0 mm | 16% | 2.5 m/s | 6.5 |
| 2024 | 41.3°C | 33.7°C | 26.1°C | 44.1°C | 23.5°C | 0 mm | 18% | 2.6 m/s | 6.6 |
| 2023 | 42.3°C | 34.6°C | 26.9°C | 44.6°C | 23.8°C | 0 mm | 14% | 2.5 m/s | 6.6 |
| 2022 | 40.8°C | 33.0°C | 25.1°C | 43.8°C | 19.8°C | 0 mm | 16% | 2.3 m/s | 6.7 |
| 2021 | 40.0°C | 32.2°C | 24.3°C | 43.7°C | 18.7°C | 0 mm | 16% | 3.1 m/s | 6.9 |
| 2020 | 40.7°C | 33.0°C | 25.4°C | 42.7°C | 22.2°C | 0 mm | 15% | 2.4 m/s | 6.7 |
| 2019 | 41.8°C | 34.1°C | 26.3°C | 45.1°C | 23.6°C | 0 mm | 17% | 2.4 m/s | 6.8 |
| 2018 🔥 | 42.4°C | 34.7°C | 26.9°C | 45.5°C | 21.8°C | 0 mm | 15% | 2.5 m/s | 6.7 |
| 2017 | 41.0°C | 33.2°C | 25.4°C | 43.5°C | 21.9°C | 0 mm | 13% | 2.4 m/s | 6.8 |
| 2016 | 40.8°C | 33.1°C | 25.5°C | 45.0°C | 20.5°C | 0 mm | 16% | 2.5 m/s | 6.7 |
| 2015 | 40.6°C | 33.2°C | 25.8°C | 44.7°C | 20.4°C | 0 mm | 16% | 2.3 m/s | 6.6 |
| 2014 | 40.3°C | 32.6°C | 24.9°C | 43.6°C | 21.0°C | 0 mm | 16% | 2.4 m/s | 6.6 |
| 2013 | 40.1°C | 32.3°C | 24.4°C | 43.5°C | 18.4°C | 0 mm | 15% | 2.4 m/s | 6.7 |
| 2012 | 40.1°C | 32.2°C | 24.4°C | 43.6°C | 22.1°C | 0 mm | 15% | 2.6 m/s | 6.8 |
| 2011 | 40.9°C | 32.8°C | 24.8°C | 43.3°C | 22.6°C | 0 mm | 15% | 2.6 m/s | 6.8 |
| 2010 | 40.8°C | 33.0°C | 25.3°C | 44.3°C | 22.8°C | 0 mm | 15% | 2.4 m/s | 6.8 |
| 2009 | 41.2°C | 33.0°C | 24.8°C | 44.3°C | 21.6°C | 0 mm | 15% | 2.4 m/s | 6.7 |
| 2008 | 41.0°C | 33.3°C | 25.5°C | 44.1°C | 22.2°C | 0 mm | 17% | 2.1 m/s | 6.5 |
| 2007 | 40.7°C | 32.9°C | 25.2°C | 44.2°C | 21.7°C | 0 mm | 14% | 2.6 m/s | 6.8 |
| 2006 | 40.0°C | 32.0°C | 24.0°C | 42.9°C | 20.2°C | 0 mm | 14% | 2.3 m/s | 7 |
| 2005 | 40.2°C | 32.1°C | 24.0°C | 44.3°C | 20.9°C | 0 mm | 14% | 2.5 m/s | 7 |
| 2004 | 40.1°C | 32.0°C | 24.0°C | 43.6°C | 19.7°C | 0 mm | 14% | 2.4 m/s | 7 |
| 2003 | 39.6°C | 31.6°C | 23.6°C | 43.9°C | 19.9°C | 0 mm | 15% | 2.5 m/s | 6.9 |
| 2002 | 40.8°C | 32.9°C | 25.0°C | 42.9°C | 21.3°C | 0 mm | 14% | 2.2 m/s | 6.8 |
| 2001 | 40.8°C | 32.9°C | 24.9°C | 43.5°C | 22.4°C | 0 mm | 14% | 2.5 m/s | 6.7 |
| 2000 | 39.6°C | 31.5°C | 23.5°C | 41.3°C | 21.3°C | 0 mm | 15% | 2.6 m/s | 6.7 |
| 1999 | 41.1°C | 33.3°C | 25.5°C | 44.6°C | 21.2°C | 0 mm | 17% | 2.7 m/s | 6.6 |
| 1998 | 41.7°C | 34.0°C | 26.4°C | 44.4°C | 22.8°C | 0 mm | 16% | 2.5 m/s | 6.6 |
| 1997 | 41.1°C | 32.9°C | 24.8°C | 43.0°C | 21.9°C | 0 mm | 14% | 2.2 m/s | 6.8 |
| 1996 | 39.6°C | 31.8°C | 24.0°C | 42.9°C | 20.5°C | 0 mm | 17% | 2.6 m/s | 6.5 |
| 1995 | 39.6°C | 31.6°C | 23.7°C | 42.1°C | 19.9°C | 0 mm | 16% | 2.4 m/s | 6.8 |
| 1994 | 39.4°C | 31.8°C | 24.2°C | 41.6°C | 22.1°C | 0 mm | 19% | 2.3 m/s | 6.5 |
| 1993 | 39.9°C | 32.0°C | 24.1°C | 42.5°C | 21.6°C | 0 mm | 15% | 2.4 m/s | 6.6 |
| 1992 | 39.3°C | 31.4°C | 23.6°C | 40.9°C | 19.2°C | 0 mm | 15% | 2.4 m/s | 6.4 |
| 1991 | 40.0°C | 31.7°C | 23.5°C | 41.8°C | 20.4°C | 0 mm | 15% | 2.5 m/s | 6.2 |
| 1990 | 40.3°C | 32.1°C | 23.9°C | 43.3°C | 19.9°C | 0 mm | 13% | 2.3 m/s | 6.5 |
| 1989 | 39.2°C | 31.4°C | 23.6°C | 43.1°C | 18.0°C | 0 mm | 15% | 2.4 m/s | 6.2 |
| 1988 | 40.4°C | 32.1°C | 23.7°C | 43.9°C | 19.6°C | 0 mm | 16% | 2.9 m/s | 6.2 |
| 1987 | 41.4°C | 33.1°C | 24.9°C | 43.4°C | 22.3°C | 0 mm | 15% | 2.6 m/s | 6.6 |
| 1986 | 39.9°C | 31.8°C | 23.6°C | 42.1°C | 20.9°C | 0 mm | 15% | 2.2 m/s | 6.6 |
| 1985 | 39.9°C | 31.9°C | 23.9°C | 43.0°C | 19.6°C | 0 mm | 14% | 2.4 m/s | 6.7 |
| 1984 | 39.7°C | 31.7°C | 23.7°C | 42.2°C | 21.3°C | 0 mm | 14% | 2.7 m/s | 6.5 |
| 1983 ❄️ | 39.5°C | 31.3°C | 23.2°C | 42.0°C | 20.1°C | 0 mm | 13% | 2.2 m/s | — |
| 1982 🌧️ | 40.7°C | 32.6°C | 24.4°C | 42.9°C | 22.6°C | 1 mm | 15% | 2.3 m/s | — |
| 1981 | 39.6°C | 31.5°C | 23.4°C | 41.3°C | 20.4°C | 0 mm | 14% | 2.3 m/s | — |
Actual recorded September data for each year, 1981–2025 — sourced from NASA POWER.
The average high in September is around 40.5°C with lows near 24.7°C (mean 32.6°C), based on 45 years of NASA POWER data.
September averages 0 mm of rainfall in Riyadh, about average for rainfall. The wettest on record was 1 mm in 1982.
The hottest September reached 45.5°C in 2018. The coldest dipped to 18°C in 1989.
Comparing the earliest years on record (1981–1985) with the most recent (2021–2025), average September temperatures have risen by about 1.6°C. Daytime highs moved from 39.9°C to 41.2°C and overnight lows from 23.7°C to 25.6°C over the same span.
September is one of the warmer months of the year in Riyadh and about average for rainfall, so plan for around 40.5°C daytime highs and 24.7°C at night.
Not quite — September is the 9th coolest month in Riyadh, averaging 32.6°C.
For September in Riyadh, pack light, breathable clothing and sun protection, with typical highs of 40.5°C and lows of 24.7°C.
Relative humidity in September averages 15% — relatively dry.
Average wind speed in September is 2.5 m/s. The windiest September on record averaged 3.1 m/s (2021).
The wettest September on record was 1982 with 1 mm. On average, September sees 0 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 Riyadh 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.
