September is one of the warmer months of the year in New Braunfels, with average highs near 33°C and lows around 21.2°C (mean 27.1°C). It is about average for rainfall, averaging 75 mm of rainfall and 66% relative humidity across the period.
September is one of the warmer months of the year in New Braunfels. Across 45 years of records, the warmest September in New Braunfels was 2023 — when the month averaged 31.5°C — while the coldest was 2001 at 24.4°C. Typical September days reach 33°C with nights near 21.2°C. The long-term trend is warming, about 0.4°C per decade.
September is about average for rainfall in New Braunfels, averaging 75 mm of rainfall. The wettest September on record was 2018 with 206 mm, while the driest was 2008 at 10 mm.
Relative humidity in New Braunfels during September averages 66%. The most humid September was 2007 at 82%, and the least humid was 2011 at 47%.
September receives about 5.3 kWh/m²/day of solar energy in New Braunfels. The sunniest September was 2011 at 6.1 kWh/m²/day, and the cloudiest was 2018 at 4.2.
Average wind speed in New Braunfels during September is 2.4 m/s. The windiest September was 1984 at 3.1 m/s, while the calmest was 2022 at 1.8 m/s.
Ranked against the other 11 months using 1981–2025 averages.
| Metric | 1980s | 1990s | 2000s | 2010s | 2020s | Change |
|---|---|---|---|---|---|---|
| Avg Temp | 26.8°C | 26.9°C | 26.4°C | 27.5°C | 28.7°C | +1.9°C |
| Avg High | 33.0°C | 32.8°C | 32.0°C | 33.1°C | 35.2°C | +2.2°C |
| Avg Low | 20.6°C | 20.9°C | 20.8°C | 21.8°C | 22.2°C | +1.6°C |
| Avg Rain | 64 mm | 68 mm | 81 mm | 99 mm | 56 mm | -8 mm |
September temperatures in New Braunfels have risen by about 2.8°C between 1981–1985 and 2021–2025.
September has ranged from a record low of 8.3°C (1983) to a record high of 45°C (2000).
Rainfall in September is about average for rainfall, averaging 75 mm, with a wettest year of 206 mm.
A good time to visit New Braunfels
September is a good time to visit New Braunfels, with days averaging 33°C and nights around 21.2°C (mean 27.1°C, warmer than New Braunfels's yearly average) and moderate rainfall. April and October are marginally more temperate, but September still suits most travellers.
| Year | Avg High | Avg Temp | Avg Low | Hottest Day | Coldest Day | Rainfall | Humidity | Wind | Solar |
|---|---|---|---|---|---|---|---|---|---|
| 2025 | 36.7°C | 29.6°C | 22.5°C | 41.0°C | 18.5°C | 17 mm | 51% | 2 m/s | 5.7 |
| 2024 | 35.2°C | 28.6°C | 22.0°C | 37.7°C | 16.5°C | 61 mm | 62% | 2.4 m/s | 5.5 |
| 2023 🔥 | 38.3°C | 31.5°C | 24.7°C | 42.8°C | 22.1°C | 26 mm | 55% | 2.3 m/s | 5.8 |
| 2022 | 35.1°C | 28.5°C | 21.8°C | 37.8°C | 16.3°C | 24 mm | 62% | 1.8 m/s | 5.8 |
| 2021 | 35.2°C | 28.6°C | 21.9°C | 39.1°C | 14.7°C | 83 mm | 59% | 2.2 m/s | 5.9 |
| 2020 | 30.5°C | 25.5°C | 20.4°C | 34.1°C | 11.3°C | 127 mm | 73% | 3 m/s | 4.7 |
| 2019 | 37.1°C | 30.6°C | 24.2°C | 39.4°C | 21.9°C | 43 mm | 60% | 2.7 m/s | 5.7 |
| 2018 🌧️ | 30.4°C | 26.2°C | 22.1°C | 38.5°C | 16.5°C | 206 mm | 82% | 2.2 m/s | 4.2 |
| 2017 | 30.0°C | 25.0°C | 20.0°C | 33.1°C | 13.7°C | 68 mm | 78% | 2.2 m/s | 5.4 |
| 2016 | 31.6°C | 26.7°C | 21.8°C | 35.5°C | 14.3°C | 74 mm | 77% | 2 m/s | 5.5 |
| 2015 | 35.4°C | 29.0°C | 22.7°C | 39.5°C | 17.3°C | 29 mm | 61% | 2.3 m/s | 5.6 |
| 2014 | 32.9°C | 27.4°C | 21.9°C | 38.0°C | 16.0°C | 88 mm | 70% | 2.4 m/s | 4.9 |
| 2013 | 33.5°C | 27.8°C | 22.0°C | 38.8°C | 15.2°C | 109 mm | 67% | 2.3 m/s | 5.2 |
| 2012 | 32.9°C | 26.7°C | 20.5°C | 39.8°C | 16.0°C | 147 mm | 66% | 2.4 m/s | 5.6 |
| 2011 | 36.6°C | 29.1°C | 21.7°C | 40.4°C | 17.0°C | 33 mm | 47% | 2.5 m/s | 6.1 |
| 2010 | 30.9°C | 26.2°C | 21.6°C | 36.6°C | 11.4°C | 197 mm | 78% | 2.4 m/s | 5 |
| 2009 | 30.2°C | 25.5°C | 20.7°C | 37.3°C | 14.5°C | 134 mm | 74% | 2.3 m/s | 4.3 |
| 2008 | 32.8°C | 26.3°C | 19.8°C | 38.0°C | 15.4°C | 10 mm | 61% | 2.3 m/s | 5.7 |
| 2007 | 30.1°C | 25.6°C | 21.2°C | 31.7°C | 18.2°C | 54 mm | 82% | 1.9 m/s | 5.1 |
| 2006 | 32.5°C | 26.6°C | 20.8°C | 38.4°C | 14.9°C | 84 mm | 65% | 2.5 m/s | 5.1 |
| 2005 | 36.3°C | 30.0°C | 23.7°C | 42.1°C | 20.8°C | 40 mm | 61% | 2.4 m/s | 5.6 |
| 2004 | 33.7°C | 27.4°C | 21.2°C | 36.8°C | 18.6°C | 46 mm | 64% | 2.2 m/s | 5 |
| 2003 | 29.9°C | 24.8°C | 19.7°C | 34.6°C | 13.8°C | 149 mm | 76% | 2.2 m/s | 4.7 |
| 2002 | 30.3°C | 25.1°C | 20.0°C | 35.8°C | 13.9°C | 161 mm | 74% | 2.7 m/s | 5.1 |
| 2001 ❄️ | 29.2°C | 24.4°C | 19.5°C | 32.7°C | 10.6°C | 84 mm | 79% | 2.1 m/s | 5.7 |
| 2000 | 35.1°C | 28.0°C | 20.9°C | 45.0°C | 9.7°C | 46 mm | 54% | 2.7 m/s | 5.9 |
| 1999 | 35.4°C | 28.3°C | 21.2°C | 40.2°C | 13.6°C | 15 mm | 51% | 2.6 m/s | 5.9 |
| 1998 | 32.3°C | 27.6°C | 22.8°C | 36.4°C | 20.1°C | 75 mm | 75% | 2.4 m/s | 5.1 |
| 1997 | 35.5°C | 28.9°C | 22.3°C | 39.0°C | 16.3°C | 41 mm | 60% | 2.5 m/s | 5.6 |
| 1996 | 30.3°C | 25.4°C | 20.4°C | 33.9°C | 10.9°C | 109 mm | 77% | 1.9 m/s | 5.3 |
| 1995 | 33.5°C | 27.3°C | 21.0°C | 38.8°C | 9.8°C | 81 mm | 66% | 2.2 m/s | 5.5 |
| 1994 | 31.4°C | 25.2°C | 18.9°C | 37.5°C | 9.7°C | 87 mm | 67% | 2.2 m/s | 5.3 |
| 1993 | 34.2°C | 27.4°C | 20.7°C | 37.6°C | 14.2°C | 36 mm | 57% | 2.6 m/s | 5.4 |
| 1992 | 33.5°C | 27.3°C | 21.2°C | 38.3°C | 11.6°C | 47 mm | 64% | 2.9 m/s | 5.5 |
| 1991 | 30.2°C | 25.0°C | 19.7°C | 33.5°C | 12.1°C | 119 mm | 74% | 2.3 m/s | 4.7 |
| 1990 | 31.8°C | 26.5°C | 21.2°C | 36.1°C | 12.3°C | 71 mm | 71% | 1.9 m/s | 5.1 |
| 1989 | 33.4°C | 26.2°C | 19.1°C | 39.4°C | 11.3°C | 26 mm | 53% | 2.6 m/s | 5.9 |
| 1988 | 34.6°C | 28.1°C | 21.6°C | 38.6°C | 16.0°C | 61 mm | 60% | 3 m/s | 5 |
| 1987 | 33.0°C | 26.7°C | 20.4°C | 37.0°C | 14.3°C | 50 mm | 65% | 2.4 m/s | 5.6 |
| 1986 | 31.7°C | 27.2°C | 22.7°C | 34.7°C | 20.7°C | 97 mm | 77% | 2.8 m/s | 5 |
| 1985 | 32.8°C | 26.9°C | 20.9°C | 41.2°C | 8.8°C | 131 mm | 65% | 3 m/s | 5.2 |
| 1984 | 32.3°C | 26.1°C | 19.8°C | 37.4°C | 9.5°C | 37 mm | 60% | 3.1 m/s | 5.1 |
| 1983 | 32.2°C | 26.2°C | 20.2°C | 38.0°C | 8.3°C | 80 mm | 68% | 2.8 m/s | — |
| 1982 | 34.3°C | 27.7°C | 21.0°C | 38.4°C | 13.3°C | 47 mm | 60% | 2.4 m/s | — |
| 1981 | 32.3°C | 26.2°C | 20.1°C | 34.7°C | 11.5°C | 45 mm | 68% | 2.3 m/s | — |
Actual recorded September data for each year, 1981–2025 — sourced from NASA POWER.
The average high in September is around 33°C with lows near 21.2°C (mean 27.1°C), based on 45 years of NASA POWER data.
September averages 75 mm of rainfall in New Braunfels, about average for rainfall. The wettest on record was 206 mm in 2018.
The hottest September reached 45°C in 2000. The coldest dipped to 8.3°C in 1983.
Comparing the earliest years on record (1981–1985) with the most recent (2021–2025), average September temperatures have risen by about 2.8°C. Daytime highs moved from 32.8°C to 36.1°C and overnight lows from 20.4°C to 22.6°C over the same span.
September is one of the warmer months of the year in New Braunfels and about average for rainfall, so plan for around 33°C daytime highs and 21.2°C at night.
Not quite — September is the 9th coolest month in New Braunfels, averaging 27.1°C.
For September in New Braunfels, pack light, breathable clothing and sun protection, with typical highs of 33°C and lows of 21.2°C. Bring an umbrella or light rain jacket too.
Relative humidity in September averages 66% — moderately humid.
Average wind speed in September is 2.4 m/s. The windiest September on record averaged 3.1 m/s (1984).
The wettest September on record was 2018 with 206 mm. On average, September sees 75 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 New Braunfels 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.
