September is one of the warmer months of the year in Penzance, with average highs near 16.3°C and lows around 14.9°C (mean 15.6°C). It is one of the drier months, averaging 72 mm of rainfall and 85% relative humidity across the period.
September is one of the warmer months of the year in Penzance. Across 45 years of records, the warmest September in Penzance was 2023 — when the month averaged 17.3°C — while the coldest was 1986 at 13.5°C. Typical September days reach 16.3°C with nights near 14.9°C. The long-term trend is warming, about 0.2°C per decade.
September is one of the drier months in Penzance, averaging 72 mm of rainfall. The wettest September on record was 1993 with 145 mm, while the driest was 2014 at 8 mm.
Relative humidity in Penzance during September averages 85%. The most humid September was 1985 at 89%, and the least humid was 1990 at 82%.
September receives about 3.4 kWh/m²/day of solar energy in Penzance. The sunniest Septembers were 1996 and 2014 at 3.9 kWh/m²/day, and the cloudiest was 2000 at 2.9.
Average wind speed in Penzance during September is 5.7 m/s. The windiest September was 2017 at 6.8 m/s, while the calmest was 2014 at 4.2 m/s.
Ranked against the other 11 months using 1981–2025 averages.
| Metric | 1980s | 1990s | 2000s | 2010s | 2020s | Change |
|---|---|---|---|---|---|---|
| Avg Temp | 15.2°C | 15.3°C | 15.8°C | 15.6°C | 16.3°C | +1.1°C |
| Avg High | 15.9°C | 16.1°C | 16.5°C | 16.2°C | 17.0°C | +1.1°C |
| Avg Low | 14.5°C | 14.6°C | 15.1°C | 14.9°C | 15.6°C | +1.1°C |
| Avg Rain | 72 mm | 79 mm | 53 mm | 72 mm | 94 mm | +22 mm |
September temperatures in Penzance have risen by about 1°C between 1981–1985 and 2021–2025.
September has ranged from a record low of 11.2°C (1986) to a record high of 20.6°C (2023).
Rainfall in September is one of the drier months, averaging 72 mm, with a wettest year of 145 mm.
One of the best times to visit Penzance
September is one of the best times to visit Penzance. Expect days averaging 16.3°C and nights around 14.9°C (mean 15.6°C) — warmer than Penzance's yearly average — with moderate rainfall (72 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 | 16.4°C | 15.8°C | 15.1°C | 18.2°C | 13.2°C | 87 mm | 82% | 6.3 m/s | 3.5 |
| 2024 | 16.4°C | 15.7°C | 14.9°C | 18.5°C | 12.8°C | 88 mm | 85% | 6 m/s | 3 |
| 2023 🔥 | 18.0°C | 17.3°C | 16.6°C | 20.6°C | 14.6°C | 102 mm | 88% | 5.3 m/s | 3.4 |
| 2022 | 17.3°C | 16.6°C | 16.0°C | 19.6°C | 13.7°C | 107 mm | 83% | 6.2 m/s | 3.3 |
| 2021 | 17.4°C | 16.7°C | 16.0°C | 20.0°C | 13.8°C | 79 mm | 88% | 4.8 m/s | 3.1 |
| 2020 | 16.5°C | 15.8°C | 15.1°C | 18.2°C | 11.7°C | 101 mm | 85% | 5.4 m/s | 3.4 |
| 2019 | 16.6°C | 16.0°C | 15.4°C | 17.7°C | 14.0°C | 104 mm | 85% | 6.7 m/s | 3.5 |
| 2018 | 16.3°C | 15.6°C | 14.9°C | 18.4°C | 13.2°C | 57 mm | 84% | 5.6 m/s | 3.4 |
| 2017 | 15.8°C | 15.1°C | 14.5°C | 17.4°C | 12.3°C | 112 mm | 85% | 6.8 m/s | 3.3 |
| 2016 | 16.9°C | 16.3°C | 15.8°C | 18.5°C | 13.8°C | 97 mm | 87% | 6.1 m/s | 3.1 |
| 2015 | 15.4°C | 14.8°C | 14.1°C | 17.1°C | 12.9°C | 50 mm | 83% | 6 m/s | 3.8 |
| 2014 | 17.3°C | 16.5°C | 15.7°C | 18.3°C | 14.6°C | 8 mm | 87% | 4.2 m/s | 3.9 |
| 2013 | 16.1°C | 15.4°C | 14.7°C | 17.8°C | 13.4°C | 59 mm | 87% | 5.3 m/s | 3 |
| 2012 | 15.8°C | 15.1°C | 14.3°C | 17.6°C | 12.0°C | 83 mm | 82% | 5.5 m/s | 3.4 |
| 2011 | 16.0°C | 15.4°C | 14.8°C | 17.3°C | 13.3°C | 62 mm | 88% | 6.5 m/s | 3.3 |
| 2010 | 16.2°C | 15.6°C | 15.0°C | 17.7°C | 12.1°C | 88 mm | 85% | 5.5 m/s | 3.5 |
| 2009 | 15.9°C | 15.2°C | 14.5°C | 17.0°C | 13.6°C | 35 mm | 85% | 5.4 m/s | 3.6 |
| 2008 | 15.8°C | 15.1°C | 14.5°C | 16.6°C | 13.7°C | 76 mm | 84% | 5.6 m/s | 3.5 |
| 2007 | 16.4°C | 15.6°C | 14.9°C | 18.6°C | 11.6°C | 32 mm | 84% | 5.3 m/s | 3.7 |
| 2006 | 17.5°C | 16.9°C | 16.2°C | 19.1°C | 15.5°C | 56 mm | 89% | 6 m/s | 3.5 |
| 2005 | 17.2°C | 16.5°C | 15.7°C | 18.4°C | 13.4°C | 62 mm | 84% | 5.4 m/s | 3.4 |
| 2004 | 16.4°C | 15.8°C | 15.2°C | 19.8°C | 13.1°C | 52 mm | 86% | 6.5 m/s | 3.5 |
| 2003 | 17.0°C | 16.2°C | 15.4°C | 18.6°C | 13.0°C | 33 mm | 83% | 4.9 m/s | 3.6 |
| 2002 | 16.5°C | 15.8°C | 15.0°C | 17.8°C | 13.6°C | 28 mm | 84% | 5.2 m/s | 3.8 |
| 2001 | 15.9°C | 15.3°C | 14.6°C | 17.4°C | 13.1°C | 38 mm | 85% | 6 m/s | 3.5 |
| 2000 | 16.5°C | 15.9°C | 15.2°C | 18.8°C | 12.7°C | 122 mm | 88% | 5.8 m/s | 2.9 |
| 1999 | 17.1°C | 16.4°C | 15.7°C | 20.2°C | 14.1°C | 97 mm | 85% | 5.8 m/s | 3.5 |
| 1998 | 16.3°C | 15.8°C | 15.2°C | 17.8°C | 13.3°C | 92 mm | 89% | 6.4 m/s | 3.3 |
| 1997 | 16.5°C | 15.9°C | 15.3°C | 17.3°C | 13.4°C | 33 mm | 87% | 5.3 m/s | 3.5 |
| 1996 | 15.9°C | 15.0°C | 14.2°C | 18.0°C | 12.5°C | 40 mm | 84% | 5.6 m/s | 3.9 |
| 1995 | 16.0°C | 15.3°C | 14.6°C | 17.5°C | 12.5°C | 81 mm | 84% | 6.1 m/s | 3.5 |
| 1994 | 14.9°C | 14.2°C | 13.5°C | 16.7°C | 11.8°C | 94 mm | 85% | 6.3 m/s | 3.1 |
| 1993 🌧️ | 15.3°C | 14.6°C | 13.9°C | 17.7°C | 11.4°C | 145 mm | 83% | 6.1 m/s | 3.4 |
| 1992 | 14.9°C | 14.2°C | 13.6°C | 15.9°C | 11.9°C | 108 mm | 86% | 6.1 m/s | 3.2 |
| 1991 | 17.0°C | 16.2°C | 15.5°C | 19.5°C | 12.3°C | 55 mm | 85% | 5.1 m/s | 3.6 |
| 1990 | 16.6°C | 15.7°C | 14.8°C | 19.0°C | 13.1°C | 42 mm | 82% | 5.6 m/s | 3.7 |
| 1989 | 16.9°C | 16.1°C | 15.3°C | 18.7°C | 13.2°C | 50 mm | 84% | 5.4 m/s | 3 |
| 1988 | 15.0°C | 14.4°C | 13.8°C | 17.3°C | 11.4°C | 54 mm | 85% | 6.1 m/s | 3.2 |
| 1987 | 16.4°C | 15.7°C | 15.0°C | 18.4°C | 12.2°C | 81 mm | 84% | 5.1 m/s | 3.4 |
| 1986 ❄️ | 14.3°C | 13.5°C | 12.6°C | 15.2°C | 11.2°C | 37 mm | 83% | 4.4 m/s | 3.4 |
| 1985 | 15.8°C | 15.1°C | 14.5°C | 17.4°C | 12.7°C | 41 mm | 89% | 5.2 m/s | 3.4 |
| 1984 | 16.1°C | 15.4°C | 14.7°C | 19.1°C | 11.8°C | 93 mm | 82% | 6.2 m/s | 3.4 |
| 1983 | 15.5°C | 14.8°C | 14.1°C | 17.9°C | 12.3°C | 94 mm | 87% | 6.6 m/s | — |
| 1982 | 16.4°C | 15.6°C | 14.8°C | 18.9°C | 12.8°C | 79 mm | 87% | 4.9 m/s | — |
| 1981 | 17.0°C | 16.2°C | 15.5°C | 18.8°C | 12.9°C | 119 mm | 84% | 6.1 m/s | — |
Actual recorded September data for each year, 1981–2025 — sourced from NASA POWER.
The average high in September is around 16.3°C with lows near 14.9°C (mean 15.6°C), based on 45 years of NASA POWER data.
September averages 72 mm of rainfall in Penzance, one of the drier months. The wettest on record was 145 mm in 1993.
The hottest September reached 20.6°C in 2023. The coldest dipped to 11.2°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°C. Daytime highs moved from 16.2°C to 17.1°C and overnight lows from 14.7°C to 15.7°C over the same span.
September is one of the warmer months of the year in Penzance and one of the drier months, so plan for around 16.3°C daytime highs and 14.9°C at night.
Not quite — September is the 10th coolest month in Penzance, averaging 15.6°C.
For September in Penzance, pack light layers you can adjust through the day, with typical highs of 16.3°C and lows of 14.9°C. Bring an umbrella or light rain jacket too.
Relative humidity in September averages 85% — quite humid.
Average wind speed in September is 5.7 m/s. The windiest September on record averaged 6.8 m/s (2017).
The wettest September on record was 1993 with 145 mm. On average, September sees 72 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 Penzance 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.
