September is one of the warmer months of the year in Laredo, with average highs near 34.1°C and lows around 22.4°C (mean 28.3°C). It is a relatively wet time of year, averaging 86 mm of rainfall and 65% relative humidity across the period.
September is one of the warmer months of the year in Laredo. Across 45 years of records, the warmest September in Laredo was 2023 — when the month averaged 31.7°C — while the coldest was 2008 at 25.7°C. Typical September days reach 34.1°C with nights near 22.4°C. The long-term trend is warming, about 0.3°C per decade.
September is a relatively wet time of year in Laredo, averaging 86 mm of rainfall. The wettest September on record was 2018 with 249 mm, while the driest was 1982 at 23 mm.
Relative humidity in Laredo during September averages 65%. The most humid September was 2018 at 78%, and the least humid was 2011 at 50%.
September receives about 5.5 kWh/m²/day of solar energy in Laredo. The sunniest September was 2023 at 6.4 kWh/m²/day, and the cloudiest were 2003, 2009 and 2018 at 4.7.
Average wind speed in Laredo during September is 3 m/s. The windiest September was 1986 at 4.4 m/s, while the calmest was 2008 at 2.1 m/s.
Ranked against the other 11 months using 1981–2025 averages.
| Metric | 1980s | 1990s | 2000s | 2010s | 2020s | Change |
|---|---|---|---|---|---|---|
| Avg Temp | 28.2°C | 27.7°C | 27.5°C | 28.8°C | 29.4°C | +1.2°C |
| Avg High | 34.4°C | 33.6°C | 33.0°C | 34.4°C | 35.5°C | +1.1°C |
| Avg Low | 22.0°C | 21.9°C | 21.9°C | 23.2°C | 23.4°C | +1.4°C |
| Avg Rain | 50 mm | 82 mm | 106 mm | 114 mm | 63 mm | +13 mm |
September temperatures in Laredo have risen by about 1.8°C between 1981–1985 and 2021–2025.
September has ranged from a record low of 10.2°C (1984) to a record high of 44.1°C (2000).
Rainfall in September is a relatively wet time of year, averaging 86 mm, with a wettest year of 249 mm.
Daytime highs and overnight lows have shifted differently — highs rose about 0.2°C per decade while lows rose 0.4°C per decade, narrowing the gap between day and night.
A good time to visit Laredo
September is a good time to visit Laredo, with days averaging 34.1°C and nights around 22.4°C (mean 28.3°C, warmer than Laredo's yearly average) and higher rainfall. March 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 | 36.3°C | 30.2°C | 24.1°C | 41.1°C | 19.7°C | 73 mm | 61% | 2.6 m/s | 5.7 |
| 2024 | 35.1°C | 29.3°C | 23.5°C | 38.8°C | 18.2°C | 94 mm | 66% | 2.6 m/s | 5.5 |
| 2023 🔥 | 38.4°C | 31.7°C | 25.0°C | 41.9°C | 22.6°C | 42 mm | 58% | 2.9 m/s | 6.4 |
| 2022 | 33.6°C | 27.9°C | 22.3°C | 35.8°C | 17.3°C | 55 mm | 70% | 2.2 m/s | 5.8 |
| 2021 | 36.6°C | 30.0°C | 23.4°C | 40.6°C | 16.4°C | 29 mm | 58% | 2.9 m/s | 6.1 |
| 2020 | 33.0°C | 27.4°C | 21.9°C | 38.2°C | 12.6°C | 83 mm | 67% | 2.8 m/s | 4.9 |
| 2019 | 36.2°C | 30.4°C | 24.6°C | 39.5°C | 22.2°C | 42 mm | 63% | 3.4 m/s | 5.7 |
| 2018 🌧️ | 31.2°C | 27.2°C | 23.2°C | 38.6°C | 18.8°C | 249 mm | 78% | 2.7 m/s | 4.7 |
| 2017 | 35.0°C | 29.0°C | 23.1°C | 40.9°C | 17.8°C | 198 mm | 61% | 3.3 m/s | 5.4 |
| 2016 | 34.5°C | 28.9°C | 23.2°C | 38.6°C | 16.0°C | 116 mm | 68% | 2.8 m/s | 5.7 |
| 2015 | 36.3°C | 29.9°C | 23.6°C | 39.9°C | 19.5°C | 37 mm | 61% | 3.3 m/s | 5.8 |
| 2014 | 32.7°C | 27.7°C | 22.7°C | 38.3°C | 18.0°C | 124 mm | 73% | 2.9 m/s | 4.9 |
| 2013 | 33.4°C | 28.1°C | 22.9°C | 39.3°C | 16.5°C | 92 mm | 70% | 3 m/s | 5.1 |
| 2012 | 35.1°C | 28.6°C | 22.1°C | 40.9°C | 17.4°C | 71 mm | 60% | 3.3 m/s | 5.8 |
| 2011 | 37.4°C | 30.3°C | 23.2°C | 41.3°C | 18.9°C | 38 mm | 50% | 2.9 m/s | 6.3 |
| 2010 | 32.4°C | 27.7°C | 22.9°C | 37.5°C | 14.9°C | 175 mm | 73% | 2.8 m/s | 5.2 |
| 2009 | 32.3°C | 27.1°C | 21.9°C | 36.3°C | 15.1°C | 120 mm | 71% | 2.6 m/s | 4.7 |
| 2008 ❄️ | 31.0°C | 25.7°C | 20.5°C | 36.7°C | 15.8°C | 88 mm | 71% | 2.1 m/s | 5.3 |
| 2007 | 32.0°C | 27.2°C | 22.3°C | 35.1°C | 19.0°C | 79 mm | 77% | 2.7 m/s | 5.5 |
| 2006 | 32.7°C | 27.5°C | 22.4°C | 38.7°C | 17.2°C | 154 mm | 69% | 2.9 m/s | 5.2 |
| 2005 | 37.0°C | 30.8°C | 24.5°C | 42.2°C | 22.8°C | 29 mm | 59% | 3.2 m/s | 5.9 |
| 2004 | 32.5°C | 27.2°C | 21.9°C | 35.4°C | 16.6°C | 120 mm | 72% | 2.5 m/s | 5.4 |
| 2003 | 30.8°C | 26.3°C | 21.8°C | 34.8°C | 16.4°C | 176 mm | 78% | 2.5 m/s | 4.7 |
| 2002 | 32.2°C | 26.7°C | 21.2°C | 35.9°C | 15.2°C | 160 mm | 71% | 2.7 m/s | 5.3 |
| 2001 | 32.6°C | 26.7°C | 20.8°C | 37.8°C | 12.8°C | 98 mm | 71% | 2.8 m/s | 5.8 |
| 2000 | 36.6°C | 29.4°C | 22.1°C | 44.1°C | 11.7°C | 37 mm | 52% | 3 m/s | 6.1 |
| 1999 | 33.9°C | 27.5°C | 21.1°C | 37.7°C | 15.0°C | 58 mm | 64% | 2.9 m/s | 5.9 |
| 1998 | 33.0°C | 28.1°C | 23.2°C | 37.3°C | 21.1°C | 137 mm | 73% | 2.7 m/s | 5 |
| 1997 | 35.5°C | 29.2°C | 22.9°C | 39.6°C | 17.3°C | 60 mm | 62% | 2.8 m/s | 5.9 |
| 1996 | 33.5°C | 27.8°C | 22.2°C | 37.5°C | 11.9°C | 69 mm | 69% | 2.7 m/s | 5.8 |
| 1995 | 33.4°C | 27.6°C | 21.7°C | 37.1°C | 11.7°C | 111 mm | 68% | 2.8 m/s | 5.7 |
| 1994 | 33.5°C | 27.0°C | 20.5°C | 38.1°C | 14.1°C | 64 mm | 62% | 2.8 m/s | 5.7 |
| 1993 | 34.6°C | 28.3°C | 22.1°C | 39.1°C | 14.5°C | 62 mm | 62% | 3.1 m/s | 5.3 |
| 1992 | 34.9°C | 28.5°C | 22.1°C | 39.6°C | 13.8°C | 50 mm | 61% | 3.3 m/s | 5.6 |
| 1991 | 31.4°C | 26.2°C | 21.1°C | 34.8°C | 14.0°C | 99 mm | 72% | 2.9 m/s | 5 |
| 1990 | 32.3°C | 27.2°C | 22.0°C | 38.5°C | 14.6°C | 109 mm | 70% | 2.6 m/s | 5.1 |
| 1989 | 33.9°C | 27.2°C | 20.4°C | 39.1°C | 11.7°C | 60 mm | 56% | 2.9 m/s | 6 |
| 1988 | 34.5°C | 28.3°C | 22.1°C | 37.3°C | 17.6°C | 98 mm | 64% | 3.5 m/s | 5.3 |
| 1987 | 34.8°C | 28.6°C | 22.4°C | 40.0°C | 16.0°C | 26 mm | 60% | 3 m/s | 5.5 |
| 1986 | 35.6°C | 29.7°C | 23.8°C | 38.2°C | 22.0°C | 23 mm | 62% | 4.4 m/s | 5.4 |
| 1985 | 34.2°C | 28.3°C | 22.4°C | 39.0°C | 12.3°C | 80 mm | 64% | 3.6 m/s | 5.7 |
| 1984 | 33.3°C | 27.2°C | 21.1°C | 37.4°C | 10.2°C | 54 mm | 60% | 3.6 m/s | 5 |
| 1983 | 33.5°C | 27.7°C | 21.8°C | 39.5°C | 13.2°C | 53 mm | 66% | 3.5 m/s | — |
| 1982 | 36.5°C | 29.6°C | 22.7°C | 39.7°C | 15.8°C | 23 mm | 53% | 3.4 m/s | — |
| 1981 | 33.1°C | 27.4°C | 21.6°C | 36.5°C | 12.9°C | 33 mm | 68% | 3 m/s | — |
Actual recorded September data for each year, 1981–2025 — sourced from NASA POWER.
The average high in September is around 34.1°C with lows near 22.4°C (mean 28.3°C), based on 45 years of NASA POWER data.
September averages 86 mm of rainfall in Laredo, a relatively wet time of year. The wettest on record was 249 mm in 2018.
The hottest September reached 44.1°C in 2000. The coldest dipped to 10.2°C in 1984.
Comparing the earliest years on record (1981–1985) with the most recent (2021–2025), average September temperatures have risen by about 1.8°C. Daytime highs moved from 34.1°C to 36°C and overnight lows from 21.9°C to 23.7°C over the same span.
September is one of the warmer months of the year in Laredo and a relatively wet time of year, so plan for around 34.1°C daytime highs and 22.4°C at night.
Not quite — September is the 8th coolest month in Laredo, averaging 28.3°C.
For September in Laredo, pack light, breathable clothing and sun protection, with typical highs of 34.1°C and lows of 22.4°C. Bring an umbrella or light rain jacket too.
Relative humidity in September averages 65% — moderately humid.
Average wind speed in September is 3 m/s. The windiest September on record averaged 4.4 m/s (1986).
The wettest September on record was 2018 with 249 mm. On average, September sees 86 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 Laredo 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.
