September is one of the warmer months of the year in Bonnyrigg, with average highs near 15.2°C and lows around 8.9°C (mean 12.1°C). It is about average for rainfall, averaging 70 mm of rainfall and 86% relative humidity across the period.
September is one of the warmer months of the year in Bonnyrigg. Across 45 years of records, the warmest September in Bonnyrigg was 2006 — when the month averaged 14.2°C — while the coldest was 1986 at 10.1°C. Typical September days reach 15.2°C with nights near 8.9°C. The long-term trend is warming, about 0.3°C per decade.
September is about average for rainfall in Bonnyrigg, averaging 70 mm of rainfall. The wettest September on record was 1985 with 130 mm, while the driest was 2014 at 22 mm.
Relative humidity in Bonnyrigg during September averages 86%. The most humid September was 1998 at 90%, and the least humid was 1991 at 82%.
September receives about 2.7 kWh/m²/day of solar energy in Bonnyrigg. The sunniest September was 1991 at 3.1 kWh/m²/day, and the cloudiest was 2000 at 2.2.
Average wind speed in Bonnyrigg during September is 3.8 m/s. The windiest September was 2012 at 4.9 m/s, while the calmest were 2002 and 2014 at 2.4 m/s.
Ranked against the other 11 months using 1981–2025 averages.
| Metric | 1980s | 1990s | 2000s | 2010s | 2020s | Change |
|---|---|---|---|---|---|---|
| Avg Temp | 11.4°C | 11.8°C | 12.4°C | 12.1°C | 12.9°C | +1.5°C |
| Avg High | 14.5°C | 15.0°C | 15.5°C | 15.2°C | 16.2°C | +1.7°C |
| Avg Low | 8.3°C | 8.6°C | 9.3°C | 8.9°C | 9.5°C | +1.2°C |
| Avg Rain | 82 mm | 67 mm | 69 mm | 67 mm | 67 mm | -15 mm |
September temperatures in Bonnyrigg have risen by about 1.4°C between 1981–1985 and 2021–2025.
September has ranged from a record low of 1.7°C (1986) to a record high of 24°C (2021).
Rainfall in September is about average for rainfall, averaging 70 mm, with a wettest year of 130 mm.
One of the best times to visit Bonnyrigg
September is one of the best times to visit Bonnyrigg. Expect days averaging 15.2°C and nights around 8.9°C (mean 12.1°C) — warmer than Bonnyrigg's yearly average — with moderate rainfall (70 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 | 16.0°C | 12.6°C | 9.1°C | 18.8°C | 3.8°C | 71 mm | 84% | 3.9 m/s | 2.8 |
| 2024 | 14.8°C | 11.5°C | 8.1°C | 20.5°C | 3.9°C | 45 mm | 88% | 3.3 m/s | 2.6 |
| 2023 | 17.5°C | 14.0°C | 10.6°C | 23.7°C | 5.8°C | 80 mm | 85% | 3.8 m/s | 2.9 |
| 2022 | 16.4°C | 13.0°C | 9.6°C | 20.9°C | 5.0°C | 96 mm | 86% | 3.6 m/s | 2.6 |
| 2021 | 17.6°C | 14.1°C | 10.7°C | 24.0°C | 6.9°C | 62 mm | 86% | 3.1 m/s | 2.6 |
| 2020 | 15.2°C | 11.9°C | 8.7°C | 19.9°C | 3.2°C | 46 mm | 86% | 4 m/s | 2.7 |
| 2019 | 15.3°C | 12.1°C | 8.9°C | 19.4°C | 5.9°C | 83 mm | 87% | 3.7 m/s | 2.8 |
| 2018 | 14.6°C | 11.4°C | 8.2°C | 19.8°C | 3.9°C | 71 mm | 85% | 4.8 m/s | 2.6 |
| 2017 | 14.9°C | 11.9°C | 8.9°C | 17.2°C | 5.3°C | 94 mm | 89% | 3.5 m/s | 2.4 |
| 2016 | 16.4°C | 13.4°C | 10.4°C | 21.3°C | 7.6°C | 72 mm | 88% | 4.1 m/s | 2.6 |
| 2015 | 15.2°C | 11.5°C | 7.8°C | 18.5°C | 5.8°C | 36 mm | 86% | 2.9 m/s | 3 |
| 2014 | 16.6°C | 13.3°C | 9.9°C | 19.4°C | 6.7°C | 22 mm | 87% | 2.4 m/s | 2.5 |
| 2013 | 14.9°C | 11.7°C | 8.6°C | 19.1°C | 5.6°C | 52 mm | 86% | 3.7 m/s | 2.6 |
| 2012 | 13.6°C | 10.8°C | 8.0°C | 18.1°C | 3.3°C | 72 mm | 87% | 4.9 m/s | 2.8 |
| 2011 | 15.2°C | 12.4°C | 9.6°C | 20.9°C | 5.6°C | 81 mm | 88% | 4.6 m/s | 2.7 |
| 2010 | 15.2°C | 12.1°C | 9.1°C | 19.4°C | 3.4°C | 87 mm | 87% | 3.9 m/s | 2.8 |
| 2009 | 15.1°C | 12.3°C | 9.6°C | 18.8°C | 6.7°C | 80 mm | 87% | 4.1 m/s | 2.6 |
| 2008 | 14.7°C | 12.0°C | 9.3°C | 17.2°C | 5.9°C | 86 mm | 89% | 3.4 m/s | 2.3 |
| 2007 | 14.6°C | 11.5°C | 8.3°C | 19.6°C | 2.5°C | 37 mm | 87% | 4 m/s | 2.8 |
| 2006 🔥 | 17.6°C | 14.2°C | 10.9°C | 21.8°C | 7.3°C | 104 mm | 87% | 3.3 m/s | 2.7 |
| 2005 | 16.0°C | 12.8°C | 9.6°C | 22.2°C | 5.0°C | 49 mm | 86% | 4.4 m/s | 2.8 |
| 2004 | 15.4°C | 12.4°C | 9.4°C | 19.8°C | 5.5°C | 56 mm | 87% | 4.7 m/s | 2.7 |
| 2003 | 16.1°C | 12.7°C | 9.2°C | 19.8°C | 4.6°C | 52 mm | 85% | 3.2 m/s | 2.8 |
| 2002 | 15.7°C | 12.5°C | 9.3°C | 18.9°C | 6.3°C | 35 mm | 88% | 2.4 m/s | 2.7 |
| 2001 | 14.5°C | 11.5°C | 8.5°C | 17.0°C | 5.3°C | 66 mm | 88% | 3.9 m/s | 2.3 |
| 2000 | 15.3°C | 12.3°C | 9.3°C | 19.3°C | 5.9°C | 126 mm | 89% | 3.5 m/s | 2.2 |
| 1999 | 16.9°C | 13.5°C | 10.1°C | 22.3°C | 6.4°C | 81 mm | 87% | 3.8 m/s | 2.7 |
| 1998 | 15.4°C | 12.6°C | 9.8°C | 21.9°C | 5.3°C | 75 mm | 90% | 3.2 m/s | 2.7 |
| 1997 | 15.0°C | 11.6°C | 8.3°C | 18.0°C | 4.9°C | 41 mm | 86% | 3.9 m/s | 3 |
| 1996 | 15.5°C | 12.3°C | 9.1°C | 21.0°C | 6.4°C | 35 mm | 83% | 3.7 m/s | 3 |
| 1995 | 15.0°C | 11.7°C | 8.4°C | 18.1°C | 3.0°C | 114 mm | 87% | 3.3 m/s | 2.6 |
| 1994 | 14.2°C | 10.9°C | 7.7°C | 17.7°C | 4.7°C | 55 mm | 84% | 3.7 m/s | 2.5 |
| 1993 | 13.9°C | 10.8°C | 7.6°C | 20.7°C | 3.1°C | 49 mm | 86% | 3.5 m/s | 2.4 |
| 1992 | 13.9°C | 11.0°C | 8.1°C | 19.3°C | 5.2°C | 110 mm | 88% | 4.2 m/s | 2.6 |
| 1991 | 16.0°C | 12.3°C | 8.6°C | 22.7°C | 4.2°C | 51 mm | 82% | 3.7 m/s | 3.1 |
| 1990 | 14.3°C | 11.1°C | 8.0°C | 19.5°C | 3.5°C | 56 mm | 83% | 4.1 m/s | 2.5 |
| 1989 | 15.1°C | 11.8°C | 8.5°C | 17.6°C | 5.8°C | 39 mm | 84% | 3.8 m/s | 2.5 |
| 1988 | 14.5°C | 11.5°C | 8.5°C | 20.4°C | 2.1°C | 69 mm | 87% | 4.5 m/s | 2.4 |
| 1987 | 13.9°C | 11.1°C | 8.2°C | 18.0°C | 2.9°C | 61 mm | 86% | 4.4 m/s | 2.9 |
| 1986 ❄️ | 13.6°C | 10.1°C | 6.7°C | 17.4°C | 1.7°C | 30 mm | 84% | 3.9 m/s | 2.9 |
| 1985 🌧️ | 14.3°C | 11.4°C | 8.6°C | 18.7°C | 4.2°C | 130 mm | 89% | 3.9 m/s | 2.4 |
| 1984 | 14.3°C | 11.3°C | 8.4°C | 19.1°C | 5.2°C | 98 mm | 83% | 3.4 m/s | 2.4 |
| 1983 | 14.3°C | 11.3°C | 8.4°C | 17.9°C | 3.9°C | 95 mm | 84% | 4.8 m/s | — |
| 1982 | 14.8°C | 11.6°C | 8.3°C | 20.8°C | 3.8°C | 94 mm | 85% | 4.8 m/s | — |
| 1981 | 15.8°C | 12.4°C | 9.1°C | 19.9°C | 6.3°C | 118 mm | 85% | 4.2 m/s | — |
Actual recorded September data for each year, 1981–2025 — sourced from NASA POWER.
The average high in September is around 15.2°C with lows near 8.9°C (mean 12.1°C), based on 45 years of NASA POWER data.
September averages 70 mm of rainfall in Bonnyrigg, about average for rainfall. The wettest on record was 130 mm in 1985.
The hottest September reached 24°C in 2021. The coldest dipped to 1.7°C in 1986.
Comparing the earliest years on record (1981–1985) with the most recent (2021–2025), average September temperatures have risen by about 1.4°C. Daytime highs moved from 14.7°C to 16.5°C and overnight lows from 8.6°C to 9.6°C over the same span.
September is one of the warmer months of the year in Bonnyrigg and about average for rainfall, so plan for around 15.2°C daytime highs and 8.9°C at night.
Not quite — September is the 9th coolest month in Bonnyrigg, averaging 12.1°C.
For September in Bonnyrigg, pack light layers you can adjust through the day, with typical highs of 15.2°C and lows of 8.9°C. Bring an umbrella or light rain jacket too.
Relative humidity in September averages 86% — quite humid.
Average wind speed in September is 3.8 m/s. The windiest September on record averaged 4.9 m/s (2012).
The wettest September on record was 1985 with 130 mm. On average, September sees 70 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 Bonnyrigg 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.
