September is one of the warmer months of the year in Stanley, with average highs near 20.5°C and lows around 7.9°C (mean 14.2°C). It is about average for rainfall, averaging 52 mm of rainfall and 64% relative humidity across the period.
September is one of the warmer months of the year in Stanley. Across 45 years of records, the warmest September in Stanley was 2024 — when the month averaged 18.8°C — while the coldest was 1985 at 10.2°C. Typical September days reach 20.5°C with nights near 7.9°C. The long-term trend is warming, about 0.8°C per decade.
September is about average for rainfall in Stanley, averaging 52 mm of rainfall. The wettest September on record was 2019 with 160 mm, while the driest was 2012 at 7 mm.
Relative humidity in Stanley during September averages 64%. The most humid September was 2019 at 77%, and the least humid was 2012 at 51%.
September receives about 3.8 kWh/m²/day of solar energy in Stanley. The sunniest September was 1989 at 4.4 kWh/m²/day, and the cloudiest were 1986 and 2019 at 3.2.
Average wind speed in Stanley during September is 3.4 m/s. The windiest September was 2020 at 3.9 m/s, while the calmest were 1987 and 2001 at 2.8 m/s.
Ranked against the other 11 months using 1981–2025 averages.
| Metric | 1980s | 1990s | 2000s | 2010s | 2020s | Change |
|---|---|---|---|---|---|---|
| Avg Temp | 12.8°C | 13.8°C | 14.6°C | 14.1°C | 16.6°C | +3.8°C |
| Avg High | 18.9°C | 20.2°C | 20.9°C | 20.3°C | 22.9°C | +4°C |
| Avg Low | 6.7°C | 7.4°C | 8.2°C | 7.9°C | 10.3°C | +3.6°C |
| Avg Rain | 47 mm | 40 mm | 51 mm | 77 mm | 41 mm | -6 mm |
September temperatures in Stanley have risen by about 5.2°C between 1981–1985 and 2021–2025.
September has ranged from a record low of -3.4°C (2018) to a record high of 36.4°C (2001).
Rainfall in September is about average for rainfall, averaging 52 mm, with a wettest year of 160 mm.
One of the best times to visit Stanley
September is one of the best times to visit Stanley. Expect days averaging 20.5°C and nights around 7.9°C (mean 14.2°C) — warmer than Stanley's yearly average — with moderate rainfall (52 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 | 23.5°C | 17.6°C | 11.6°C | 30.1°C | 2.9°C | 58 mm | 69% | 3 m/s | 3.3 |
| 2024 🔥 | 25.0°C | 18.8°C | 12.5°C | 30.7°C | 5.8°C | 61 mm | 64% | 3.5 m/s | 4 |
| 2023 | 23.7°C | 17.6°C | 11.5°C | 35.9°C | 5.2°C | 56 mm | 65% | 3 m/s | 3.6 |
| 2022 | 21.7°C | 15.5°C | 9.4°C | 32.0°C | 2.3°C | 32 mm | 64% | 3.3 m/s | 4.1 |
| 2021 | 23.7°C | 16.9°C | 10.1°C | 32.5°C | 5.6°C | 26 mm | 60% | 3.5 m/s | 4.1 |
| 2020 | 19.7°C | 13.1°C | 6.6°C | 28.7°C | -1.0°C | 15 mm | 60% | 3.9 m/s | 3.8 |
| 2019 🌧️ | 19.2°C | 13.9°C | 8.7°C | 30.1°C | 0.4°C | 160 mm | 77% | 3.2 m/s | 3.2 |
| 2018 | 18.2°C | 12.1°C | 6.0°C | 29.0°C | -3.4°C | 47 mm | 66% | 3.5 m/s | 3.4 |
| 2017 | 20.9°C | 14.8°C | 8.7°C | 33.9°C | 4.0°C | 91 mm | 66% | 3.7 m/s | 3.6 |
| 2016 | 20.3°C | 14.3°C | 8.4°C | 29.7°C | 3.2°C | 97 mm | 71% | 3.5 m/s | 3.6 |
| 2015 | 23.0°C | 16.3°C | 9.6°C | 35.1°C | 1.7°C | 84 mm | 64% | 3.4 m/s | 4 |
| 2014 | 20.3°C | 13.8°C | 7.3°C | 28.9°C | -0.3°C | 49 mm | 70% | 3.5 m/s | 3.7 |
| 2013 | 22.6°C | 16.0°C | 9.5°C | 31.7°C | 2.0°C | 46 mm | 66% | 3.3 m/s | 3.8 |
| 2012 | 21.0°C | 14.0°C | 7.1°C | 31.6°C | -2.1°C | 7 mm | 51% | 3.5 m/s | 4.1 |
| 2011 | 20.8°C | 14.2°C | 7.5°C | 29.5°C | 0.2°C | 89 mm | 64% | 3.5 m/s | 4.3 |
| 2010 | 16.8°C | 11.6°C | 6.3°C | 23.2°C | -0.2°C | 106 mm | 75% | 3.6 m/s | 3.5 |
| 2009 | 24.1°C | 17.8°C | 11.4°C | 30.4°C | -0.1°C | 63 mm | 70% | 3.2 m/s | 4.3 |
| 2008 | 19.5°C | 13.6°C | 7.7°C | 29.9°C | 3.1°C | 103 mm | 70% | 3.3 m/s | 3.8 |
| 2007 | 20.8°C | 14.2°C | 7.6°C | 31.0°C | 0.6°C | 26 mm | 62% | 3.6 m/s | 3.7 |
| 2006 | 20.2°C | 13.8°C | 7.4°C | 29.9°C | -0.7°C | 36 mm | 62% | 3.2 m/s | 4.1 |
| 2005 | 21.8°C | 15.2°C | 8.6°C | 30.2°C | 2.6°C | 21 mm | 65% | 3.2 m/s | 4.2 |
| 2004 | 21.0°C | 14.9°C | 8.8°C | 32.2°C | 4.3°C | 71 mm | 72% | 3.2 m/s | 3.6 |
| 2003 | 19.3°C | 13.6°C | 7.8°C | 31.7°C | -3.0°C | 51 mm | 65% | 3.6 m/s | 3.5 |
| 2002 | 21.6°C | 15.0°C | 8.5°C | 31.7°C | -1.9°C | 61 mm | 61% | 3.4 m/s | 3.8 |
| 2001 | 21.3°C | 14.5°C | 7.7°C | 36.4°C | -1.4°C | 32 mm | 60% | 2.8 m/s | 4 |
| 2000 | 19.0°C | 12.9°C | 6.8°C | 26.5°C | -0.8°C | 47 mm | 65% | 3.6 m/s | 3.5 |
| 1999 | 17.8°C | 12.0°C | 6.2°C | 26.8°C | -0.2°C | 38 mm | 67% | 3.4 m/s | 3.4 |
| 1998 | 22.8°C | 15.9°C | 9.0°C | 34.0°C | 2.1°C | 10 mm | 60% | 3.1 m/s | 4 |
| 1997 | 22.1°C | 15.7°C | 9.4°C | 28.7°C | 1.3°C | 25 mm | 60% | 3.7 m/s | 4.1 |
| 1996 | 19.8°C | 13.7°C | 7.5°C | 31.5°C | -1.8°C | 53 mm | 65% | 2.9 m/s | 3.7 |
| 1995 | 19.5°C | 13.2°C | 6.8°C | 31.6°C | -2.2°C | 61 mm | 61% | 3 m/s | 4.1 |
| 1994 | 22.4°C | 15.9°C | 9.4°C | 32.1°C | 2.2°C | 44 mm | 62% | 3 m/s | 4.3 |
| 1993 | 17.2°C | 11.1°C | 5.0°C | 25.9°C | -1.4°C | 16 mm | 67% | 3.6 m/s | 3.6 |
| 1992 | 19.2°C | 12.5°C | 5.8°C | 27.6°C | -2.1°C | 30 mm | 62% | 3.7 m/s | 3.5 |
| 1991 | 18.8°C | 12.6°C | 6.4°C | 30.1°C | -1.8°C | 95 mm | 65% | 3.4 m/s | 3.8 |
| 1990 | 22.4°C | 15.4°C | 8.5°C | 31.7°C | 1.3°C | 24 mm | 56% | 3.5 m/s | 4 |
| 1989 | 21.4°C | 14.3°C | 7.2°C | 32.0°C | -1.1°C | 35 mm | 57% | 3.5 m/s | 4.4 |
| 1988 | 19.6°C | 13.5°C | 7.4°C | 30.0°C | 2.4°C | 31 mm | 60% | 3.8 m/s | 3.6 |
| 1987 | 20.8°C | 14.8°C | 8.7°C | 30.7°C | 3.8°C | 43 mm | 63% | 2.8 m/s | 3.8 |
| 1986 | 17.5°C | 12.0°C | 6.4°C | 23.5°C | -0.8°C | 59 mm | 69% | 3 m/s | 3.2 |
| 1985 ❄️ | 15.8°C | 10.2°C | 4.6°C | 24.6°C | -2.7°C | 46 mm | 70% | 3.7 m/s | 3.3 |
| 1984 | 16.8°C | 10.8°C | 4.8°C | 27.8°C | -3.0°C | 26 mm | 60% | 3.4 m/s | 3.4 |
| 1983 | 18.7°C | 13.0°C | 7.3°C | 35.1°C | -2.0°C | 67 mm | 63% | 3.6 m/s | — |
| 1982 | 19.7°C | 13.3°C | 7.0°C | 32.7°C | -0.5°C | 55 mm | 62% | 3.5 m/s | — |
| 1981 | 19.8°C | 13.4°C | 7.0°C | 31.0°C | -0.3°C | 62 mm | 63% | 3.2 m/s | — |
Actual recorded September data for each year, 1981–2025 — sourced from NASA POWER.
The average high in September is around 20.5°C with lows near 7.9°C (mean 14.2°C), based on 45 years of NASA POWER data.
September averages 52 mm of rainfall in Stanley, about average for rainfall. The wettest on record was 160 mm in 2019.
The hottest September reached 36.4°C in 2001. The coldest dipped to -3.4°C in 2018.
Comparing the earliest years on record (1981–1985) with the most recent (2021–2025), average September temperatures have risen by about 5.2°C. Daytime highs moved from 18.2°C to 23.5°C and overnight lows from 6.1°C to 11°C over the same span.
September is one of the warmer months of the year in Stanley and about average for rainfall, so plan for around 20.5°C daytime highs and 7.9°C at night.
Not quite — September is the 9th coolest month in Stanley, averaging 14.2°C.
For September in Stanley, pack warm layers and a jacket for chilly mornings, with typical highs of 20.5°C and lows of 7.9°C. Bring an umbrella or light rain jacket too.
Relative humidity in September averages 64% — moderately humid.
Average wind speed in September is 3.4 m/s. The windiest September on record averaged 3.9 m/s (2020).
The wettest September on record was 2019 with 160 mm. On average, September sees 52 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 Stanley 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.
