September is one of the cooler months of the year in Roma, with average highs near 27°C and lows around 10.5°C (mean 18.8°C). It is one of the drier months, averaging 23 mm of rainfall and 48% relative humidity across the period.
September is one of the cooler months of the year in Roma. Across 45 years of records, the warmest September in Roma was 2013 — when the month averaged 22.5°C — while the coldest was 1984 at 15.1°C. Typical September days reach 27°C with nights near 10.5°C. The long-term trend is warming, about 0.5°C per decade.
September is one of the drier months in Roma, averaging 23 mm of rainfall. The wettest September on record was 2010 with 107 mm, while the driest was 2003 at 0 mm.
Relative humidity in Roma during September averages 48%. The most humid September was 1998 at 73%, and the least humid was 2017 at 29%.
September receives about 6 kWh/m²/day of solar energy in Roma. The sunniest September was 2003 at 6.6 kWh/m²/day, and the cloudiest was 2010 at 4.7.
Average wind speed in Roma during September is 2.8 m/s. The windiest Septembers were 1988, 2002 and 2021 at 3.2 m/s, while the calmest were 1981 and 2010 at 2.4 m/s.
Ranked against the other 11 months using 1981–2025 averages.
| Metric | 1980s | 1990s | 2000s | 2010s | 2020s | Change |
|---|---|---|---|---|---|---|
| Avg Temp | 17.8°C | 18.1°C | 19.4°C | 19.0°C | 19.8°C | +2°C |
| Avg High | 26.0°C | 26.3°C | 27.8°C | 27.2°C | 27.9°C | +1.9°C |
| Avg Low | 9.6°C | 9.9°C | 11.1°C | 10.8°C | 11.7°C | +2.1°C |
| Avg Rain | 15 mm | 25 mm | 19 mm | 31 mm | 24 mm | +9 mm |
September temperatures in Roma have risen by about 2.1°C between 1981–1985 and 2021–2025.
September has ranged from a record low of 0.3°C (1995) to a record high of 40.4°C (2017).
Rainfall in September is one of the drier months, averaging 23 mm, with a wettest year of 107 mm.
One of the best times to visit Roma
September is one of the best times to visit Roma. Expect days averaging 27°C and nights around 10.5°C (mean 18.8°C) — cooler than Roma's yearly average — with low rainfall (23 mm), so conditions are generally comfortable for sightseeing and outdoor plans.
| Year | Avg High | Avg Temp | Avg Low | Hottest Day | Coldest Day | Rainfall | Humidity | Wind | Solar |
|---|---|---|---|---|---|---|---|---|---|
| 2025 | 28.4°C | 20.2°C | 11.9°C | 35.4°C | 5.8°C | 1 mm | 44% | 2.7 m/s | 5.8 |
| 2024 | 29.0°C | 20.5°C | 12.0°C | 36.6°C | 5.8°C | 6 mm | 40% | 2.8 m/s | 6.2 |
| 2023 | 29.8°C | 21.2°C | 12.5°C | 36.2°C | 6.1°C | 0 mm | 36% | 2.6 m/s | 6.3 |
| 2022 | 24.2°C | 17.2°C | 10.3°C | 30.0°C | 6.7°C | 103 mm | 65% | 2.6 m/s | 5.2 |
| 2021 | 27.5°C | 19.1°C | 10.7°C | 32.0°C | 4.9°C | 17 mm | 42% | 3.2 m/s | 6 |
| 2020 | 28.2°C | 20.4°C | 12.6°C | 34.3°C | 5.4°C | 14 mm | 46% | 3 m/s | 6 |
| 2019 | 28.7°C | 19.8°C | 10.9°C | 33.7°C | 4.3°C | 17 mm | 31% | 2.7 m/s | 6.4 |
| 2018 | 27.8°C | 19.6°C | 11.3°C | 33.6°C | 4.3°C | 6 mm | 42% | 2.9 m/s | 6.2 |
| 2017 | 30.6°C | 21.2°C | 11.8°C | 40.4°C | 5.3°C | 1 mm | 29% | 2.8 m/s | 6.5 |
| 2016 | 24.6°C | 17.5°C | 10.3°C | 28.2°C | 5.7°C | 100 mm | 66% | 2.9 m/s | 5.1 |
| 2015 | 26.0°C | 17.8°C | 9.5°C | 31.7°C | 5.3°C | 16 mm | 51% | 2.6 m/s | 6.2 |
| 2014 | 25.4°C | 17.4°C | 9.4°C | 31.7°C | 3.6°C | 23 mm | 54% | 2.9 m/s | 5.8 |
| 2013 🔥 | 31.8°C | 22.5°C | 13.2°C | 39.6°C | 8.9°C | 3 mm | 33% | 2.7 m/s | 6.2 |
| 2012 | 26.9°C | 18.5°C | 10.2°C | 33.4°C | 2.4°C | 9 mm | 52% | 2.7 m/s | 5.9 |
| 2011 | 25.9°C | 17.9°C | 9.8°C | 31.8°C | 3.3°C | 23 mm | 52% | 2.8 m/s | 6 |
| 2010 🌧️ | 23.9°C | 17.6°C | 11.3°C | 30.3°C | 6.0°C | 107 mm | 71% | 2.4 m/s | 4.7 |
| 2009 | 28.0°C | 19.3°C | 10.7°C | 36.2°C | 5.4°C | 39 mm | 46% | 2.8 m/s | 6 |
| 2008 | 26.1°C | 18.9°C | 11.6°C | 33.6°C | 5.7°C | 70 mm | 61% | 2.7 m/s | 5.6 |
| 2007 | 26.6°C | 18.1°C | 9.6°C | 35.1°C | 5.7°C | 19 mm | 52% | 2.5 m/s | 6 |
| 2006 | 28.0°C | 19.9°C | 11.9°C | 33.7°C | 6.2°C | 5 mm | 45% | 3 m/s | 6.1 |
| 2005 | 28.5°C | 20.2°C | 12.0°C | 34.6°C | 4.2°C | 9 mm | 50% | 2.9 m/s | 5.9 |
| 2004 | 26.7°C | 18.4°C | 10.0°C | 35.5°C | 1.9°C | 26 mm | 50% | 2.6 m/s | 6.2 |
| 2003 | 29.4°C | 20.2°C | 11.1°C | 37.0°C | 2.3°C | 0 mm | 36% | 2.7 m/s | 6.6 |
| 2002 | 28.8°C | 20.0°C | 11.2°C | 37.6°C | 4.6°C | 0 mm | 39% | 3.2 m/s | 5.9 |
| 2001 | 26.1°C | 18.1°C | 10.2°C | 31.2°C | 4.7°C | 18 mm | 52% | 2.7 m/s | 5.9 |
| 2000 | 30.2°C | 21.3°C | 12.5°C | 38.9°C | 5.2°C | 2 mm | 35% | 2.7 m/s | 6.2 |
| 1999 | 27.2°C | 19.2°C | 11.1°C | 32.2°C | 5.3°C | 8 mm | 49% | 2.9 m/s | 6.2 |
| 1998 | 24.6°C | 18.1°C | 11.7°C | 30.0°C | 4.4°C | 58 mm | 73% | 2.9 m/s | 5.4 |
| 1997 | 28.2°C | 19.9°C | 11.6°C | 34.9°C | 6.3°C | 27 mm | 47% | 2.7 m/s | 6 |
| 1996 | 27.6°C | 18.5°C | 9.5°C | 34.8°C | 2.8°C | 35 mm | 45% | 3.1 m/s | 6.1 |
| 1995 | 26.9°C | 18.7°C | 10.4°C | 31.4°C | 0.3°C | 34 mm | 49% | 2.7 m/s | 5.9 |
| 1994 | 26.8°C | 17.4°C | 8.1°C | 32.6°C | 3.0°C | 2 mm | 31% | 2.8 m/s | 6.3 |
| 1993 | 24.7°C | 17.1°C | 9.5°C | 34.6°C | 5.1°C | 40 mm | 58% | 3.1 m/s | 5.4 |
| 1992 | 25.1°C | 16.7°C | 8.3°C | 31.9°C | 3.2°C | 29 mm | 49% | 2.8 m/s | 5.8 |
| 1991 | 28.1°C | 19.1°C | 10.0°C | 34.3°C | 3.3°C | 1 mm | 31% | 2.8 m/s | 6.2 |
| 1990 | 24.2°C | 16.7°C | 9.2°C | 32.1°C | 2.7°C | 13 mm | 61% | 2.7 m/s | 6.2 |
| 1989 | 26.3°C | 17.2°C | 8.2°C | 35.6°C | 3.7°C | 1 mm | 48% | 2.7 m/s | 6.5 |
| 1988 | 26.5°C | 18.8°C | 11.1°C | 38.9°C | 4.5°C | 35 mm | 59% | 3.2 m/s | 5.9 |
| 1987 | 26.6°C | 18.1°C | 9.7°C | 30.5°C | 2.1°C | 5 mm | 45% | 2.5 m/s | 5.9 |
| 1986 | 26.5°C | 18.1°C | 9.8°C | 35.0°C | 1.2°C | 41 mm | 50% | 3.1 m/s | 5.8 |
| 1985 | 24.6°C | 16.4°C | 8.2°C | 33.3°C | 2.6°C | 7 mm | 50% | 2.8 m/s | 6.2 |
| 1984 ❄️ | 23.4°C | 15.1°C | 6.9°C | 28.5°C | 1.7°C | 19 mm | 56% | 2.6 m/s | 6.2 |
| 1983 | 25.9°C | 18.6°C | 11.3°C | 31.2°C | 4.9°C | 14 mm | 66% | 2.7 m/s | — |
| 1982 | 26.2°C | 18.3°C | 10.3°C | 34.5°C | 3.0°C | 10 mm | 41% | 2.8 m/s | — |
| 1981 | 27.6°C | 19.2°C | 10.7°C | 35.7°C | 2.1°C | 0 mm | 51% | 2.4 m/s | — |
Actual recorded September data for each year, 1981–2025 — sourced from NASA POWER.
The average high in September is around 27°C with lows near 10.5°C (mean 18.8°C), based on 45 years of NASA POWER data.
September averages 23 mm of rainfall in Roma, one of the drier months. The wettest on record was 107 mm in 2010.
The hottest September reached 40.4°C in 2017. The coldest dipped to 0.3°C in 1995.
Comparing the earliest years on record (1981–1985) with the most recent (2021–2025), average September temperatures have risen by about 2.1°C. Daytime highs moved from 25.5°C to 27.8°C and overnight lows from 9.5°C to 11.5°C over the same span.
September is one of the cooler months of the year in Roma and one of the drier months, so plan for around 27°C daytime highs and 10.5°C at night.
Not quite — September is the 5th coolest month in Roma, averaging 18.8°C.
For September in Roma, pack light layers you can adjust through the day, with typical highs of 27°C and lows of 10.5°C.
Relative humidity in September averages 48% — relatively dry.
Average wind speed in September is 2.8 m/s. The windiest September on record averaged 3.2 m/s (1988).
The wettest September on record was 2010 with 107 mm. On average, September sees 23 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 Roma 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.
