September is one of the warmer months of the year in Stanley, with average highs near 17.7°C and lows around 9°C (mean 13.4°C). It is about average for rainfall, averaging 60 mm of rainfall and 84% 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 2023 — when the month averaged 16.1°C — while the coldest was 1986 at 10.9°C. Typical September days reach 17.7°C with nights near 9°C. The long-term trend is warming, about 0.3°C per decade.
September is about average for rainfall in Stanley, averaging 60 mm of rainfall. The wettest September on record was 2024 with 118 mm, while the driest was 1986 at 15 mm.
Relative humidity in Stanley during September averages 84%. The most humid September was 2000 at 87%, and the least humid was 1991 at 78%.
September receives about 2.9 kWh/m²/day of solar energy in Stanley. The sunniest September was 1991 at 3.3 kWh/m²/day, and the cloudiest were 2000 and 2001 at 2.3.
Average wind speed in Stanley during September is 3.2 m/s. The windiest September was 1983 at 4 m/s, while the calmest was 2014 at 2 m/s.
Ranked against the other 11 months using 1981–2025 averages.
| Metric | 1980s | 1990s | 2000s | 2010s | 2020s | Change |
|---|---|---|---|---|---|---|
| Avg Temp | 12.9°C | 13.1°C | 13.7°C | 13.4°C | 14.3°C | +1.4°C |
| Avg High | 17.1°C | 17.4°C | 18.0°C | 17.8°C | 18.7°C | +1.6°C |
| Avg Low | 8.5°C | 8.8°C | 9.4°C | 8.9°C | 9.7°C | +1.2°C |
| Avg Rain | 54 mm | 65 mm | 57 mm | 58 mm | 71 mm | +17 mm |
September temperatures in Stanley have risen by about 1.3°C between 1981–1985 and 2021–2025.
September has ranged from a record low of 1°C (1986) to a record high of 28°C (2023).
Rainfall in September is about average for rainfall, averaging 60 mm, with a wettest year of 118 mm.
One of the best times to visit Stanley
September is one of the best times to visit Stanley. Expect days averaging 17.7°C and nights around 9°C (mean 13.4°C) — warmer than Stanley's yearly average — with moderate rainfall (60 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 | 18.0°C | 13.5°C | 9.0°C | 23.0°C | 3.1°C | 89 mm | 83% | 3.3 m/s | 3 |
| 2024 🌧️ | 17.5°C | 13.4°C | 9.4°C | 23.1°C | 2.9°C | 118 mm | 87% | 3.2 m/s | 2.6 |
| 2023 🔥 | 20.8°C | 16.1°C | 11.3°C | 28.0°C | 6.6°C | 73 mm | 84% | 2.9 m/s | 3 |
| 2022 | 18.3°C | 13.9°C | 9.4°C | 23.4°C | 4.0°C | 58 mm | 83% | 2.7 m/s | 2.9 |
| 2021 | 19.8°C | 15.4°C | 11.0°C | 26.1°C | 6.7°C | 55 mm | 85% | 2.6 m/s | 2.9 |
| 2020 | 18.0°C | 13.2°C | 8.4°C | 25.4°C | 3.0°C | 31 mm | 83% | 3.2 m/s | 3.2 |
| 2019 | 17.9°C | 13.5°C | 9.0°C | 22.2°C | 4.6°C | 101 mm | 84% | 3.2 m/s | 3.2 |
| 2018 | 17.9°C | 13.2°C | 8.6°C | 23.4°C | 2.8°C | 47 mm | 82% | 3.5 m/s | 2.9 |
| 2017 | 17.1°C | 12.9°C | 8.7°C | 21.6°C | 5.0°C | 77 mm | 86% | 3.2 m/s | 2.7 |
| 2016 | 19.4°C | 15.1°C | 10.8°C | 26.7°C | 6.8°C | 49 mm | 86% | 3.2 m/s | 3 |
| 2015 | 16.7°C | 12.0°C | 7.2°C | 19.8°C | 5.0°C | 46 mm | 84% | 2.6 m/s | 3.1 |
| 2014 | 19.1°C | 14.2°C | 9.2°C | 21.9°C | 5.4°C | 18 mm | 85% | 2 m/s | 2.8 |
| 2013 | 17.3°C | 12.9°C | 8.4°C | 22.4°C | 4.7°C | 33 mm | 85% | 2.9 m/s | 2.8 |
| 2012 | 16.7°C | 12.3°C | 8.0°C | 23.4°C | 3.8°C | 92 mm | 85% | 3.7 m/s | 3.1 |
| 2011 | 18.7°C | 14.4°C | 10.1°C | 25.6°C | 6.4°C | 37 mm | 82% | 3.9 m/s | 3 |
| 2010 | 17.3°C | 13.2°C | 9.2°C | 22.1°C | 3.4°C | 83 mm | 84% | 3.4 m/s | 2.7 |
| 2009 | 17.7°C | 13.6°C | 9.4°C | 23.4°C | 6.5°C | 27 mm | 85% | 3.3 m/s | 3 |
| 2008 | 17.0°C | 13.0°C | 9.1°C | 19.8°C | 6.4°C | 80 mm | 86% | 2.7 m/s | 2.6 |
| 2007 | 17.5°C | 13.1°C | 8.8°C | 22.5°C | 3.5°C | 32 mm | 85% | 3.4 m/s | 3.1 |
| 2006 | 20.4°C | 15.9°C | 11.4°C | 25.5°C | 7.1°C | 68 mm | 85% | 3.1 m/s | 3.1 |
| 2005 | 18.8°C | 14.3°C | 9.8°C | 24.2°C | 3.3°C | 53 mm | 84% | 3.1 m/s | 3.1 |
| 2004 | 18.0°C | 13.8°C | 9.6°C | 24.2°C | 5.2°C | 38 mm | 84% | 3.9 m/s | 3.1 |
| 2003 | 18.4°C | 13.3°C | 8.3°C | 22.5°C | 3.7°C | 36 mm | 84% | 2.3 m/s | 3.2 |
| 2002 | 17.7°C | 13.4°C | 9.1°C | 21.0°C | 5.5°C | 35 mm | 85% | 2.3 m/s | 2.9 |
| 2001 | 16.4°C | 12.5°C | 8.6°C | 20.4°C | 6.2°C | 88 mm | 86% | 3.7 m/s | 2.3 |
| 2000 | 18.0°C | 13.8°C | 9.7°C | 24.6°C | 4.9°C | 114 mm | 87% | 3.1 m/s | 2.3 |
| 1999 | 19.4°C | 14.9°C | 10.4°C | 25.1°C | 6.8°C | 76 mm | 85% | 2.8 m/s | 3.1 |
| 1998 | 18.1°C | 14.0°C | 9.9°C | 22.5°C | 5.5°C | 61 mm | 86% | 3.2 m/s | 2.6 |
| 1997 | 17.2°C | 13.1°C | 8.9°C | 20.7°C | 5.5°C | 20 mm | 83% | 3.2 m/s | 2.9 |
| 1996 | 17.0°C | 12.9°C | 8.7°C | 22.2°C | 4.5°C | 24 mm | 82% | 3.3 m/s | 2.7 |
| 1995 | 17.0°C | 12.7°C | 8.5°C | 20.5°C | 2.6°C | 84 mm | 84% | 3 m/s | 2.8 |
| 1994 | 15.7°C | 11.8°C | 7.8°C | 19.5°C | 4.7°C | 114 mm | 86% | 3.6 m/s | 2.7 |
| 1993 | 15.9°C | 11.8°C | 7.8°C | 23.0°C | 4.1°C | 99 mm | 84% | 3.3 m/s | 2.5 |
| 1992 | 17.2°C | 12.8°C | 8.5°C | 22.9°C | 5.5°C | 92 mm | 83% | 3.5 m/s | 3 |
| 1991 | 19.5°C | 14.1°C | 8.8°C | 26.2°C | 4.2°C | 42 mm | 78% | 3.2 m/s | 3.3 |
| 1990 | 16.7°C | 12.6°C | 8.4°C | 22.9°C | 4.6°C | 39 mm | 79% | 3.3 m/s | 2.7 |
| 1989 | 18.4°C | 14.0°C | 9.6°C | 23.7°C | 6.0°C | 30 mm | 82% | 3 m/s | 2.9 |
| 1988 | 16.4°C | 12.3°C | 8.3°C | 24.1°C | 1.6°C | 40 mm | 84% | 3.8 m/s | 2.6 |
| 1987 | 16.7°C | 12.5°C | 8.3°C | 21.6°C | 2.4°C | 54 mm | 85% | 3.3 m/s | 2.8 |
| 1986 ❄️ | 15.7°C | 10.9°C | 6.0°C | 20.6°C | 1.0°C | 15 mm | 82% | 2.7 m/s | 3.2 |
| 1985 | 18.0°C | 13.6°C | 9.1°C | 22.8°C | 5.8°C | 34 mm | 85% | 3.3 m/s | 2.8 |
| 1984 | 16.6°C | 12.7°C | 8.8°C | 23.6°C | 4.8°C | 91 mm | 83% | 3.4 m/s | 2.6 |
| 1983 | 16.5°C | 12.6°C | 8.6°C | 21.7°C | 4.4°C | 68 mm | 85% | 4 m/s | — |
| 1982 | 18.1°C | 13.4°C | 8.7°C | 24.5°C | 5.3°C | 59 mm | 84% | 3.2 m/s | — |
| 1981 | 17.9°C | 13.7°C | 9.4°C | 22.3°C | 6.1°C | 96 mm | 84% | 3.4 m/s | — |
Actual recorded September data for each year, 1981–2025 — sourced from NASA POWER.
The average high in September is around 17.7°C with lows near 9°C (mean 13.4°C), based on 45 years of NASA POWER data.
September averages 60 mm of rainfall in Stanley, about average for rainfall. The wettest on record was 118 mm in 2024.
The hottest September reached 28°C in 2023. The coldest dipped to 1°C in 1986.
Comparing the earliest years on record (1981–1985) with the most recent (2021–2025), average September temperatures have risen by about 1.3°C. Daytime highs moved from 17.4°C to 18.9°C and overnight lows from 8.9°C to 10°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 17.7°C daytime highs and 9°C at night.
Not quite — September is the 9th coolest month in Stanley, averaging 13.4°C.
For September in Stanley, pack light layers you can adjust through the day, with typical highs of 17.7°C and lows of 9°C. Bring an umbrella or light rain jacket too.
Relative humidity in September averages 84% — quite humid.
Average wind speed in September is 3.2 m/s. The windiest September on record averaged 4 m/s (1983).
The wettest September on record was 2024 with 118 mm. On average, September sees 60 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.
