September is one of the warmer months of the year in Port Saint Lucie, with average highs near 29.8°C and lows around 24.1°C (mean 27°C). It is a relatively wet time of year, averaging 175 mm of rainfall and 83% relative humidity across the period.
September is one of the warmer months of the year in Port Saint Lucie. Across 45 years of records, the warmest September in Port Saint Lucie was 2024 — when the month averaged 28.5°C — while the coldest were 1984 and 1985 at 25.9°C. Typical September days reach 29.8°C with nights near 24.1°C. The long-term trend is warming, about 0.3°C per decade.
September is a relatively wet time of year in Port Saint Lucie, averaging 175 mm of rainfall. The wettest September on record was 2017 with 326 mm, while the driest was 1988 at 56 mm.
Relative humidity in Port Saint Lucie during September averages 83%. The most humid September was 1994 at 87%, and the least humid was 2010 at 77%.
September receives about 5 kWh/m²/day of solar energy in Port Saint Lucie. The sunniest Septembers were 1986, 1989 and 2019 at 5.4 kWh/m²/day, and the cloudiest were 1994 and 2001 at 4.4.
Average wind speed in Port Saint Lucie during September is 2.2 m/s. The windiest September was 2004 at 4 m/s, while the calmest was 2015 at 1.5 m/s.
Ranked against the other 11 months using 1981–2025 averages.
| Metric | 1980s | 1990s | 2000s | 2010s | 2020s | Change |
|---|---|---|---|---|---|---|
| Avg Temp | 26.6°C | 26.7°C | 26.9°C | 27.2°C | 27.7°C | +1.1°C |
| Avg High | 29.5°C | 29.5°C | 29.7°C | 30.1°C | 30.7°C | +1.2°C |
| Avg Low | 23.7°C | 23.9°C | 24.0°C | 24.3°C | 24.6°C | +0.9°C |
| Avg Rain | 159 mm | 185 mm | 178 mm | 166 mm | 193 mm | +34 mm |
September temperatures in Port Saint Lucie have risen by about 1.6°C between 1981–1985 and 2021–2025.
September has ranged from a record low of 17°C (2022) to a record high of 35.5°C (2022).
Rainfall in September is a relatively wet time of year, averaging 175 mm, with a wettest year of 326 mm.
A quieter season to visit Port Saint Lucie
If your dates are flexible, the more temperate months of November and April tend to be the most comfortable for visiting Port Saint Lucie. That said, September — with days averaging 29.8°C and nights around 24.1°C (mean 27°C) and higher rainfall (175 mm) — can still be rewarding for travellers who don't mind the warmth, and often means fewer crowds.
| Year | Avg High | Avg Temp | Avg Low | Hottest Day | Coldest Day | Rainfall | Humidity | Wind | Solar |
|---|---|---|---|---|---|---|---|---|---|
| 2025 | 30.3°C | 27.5°C | 24.7°C | 32.0°C | 22.8°C | 158 mm | 84% | 2 m/s | 4.8 |
| 2024 🔥 | 31.4°C | 28.5°C | 25.6°C | 32.6°C | 23.9°C | 195 mm | 85% | 2.1 m/s | 4.8 |
| 2023 | 31.4°C | 28.1°C | 24.8°C | 33.6°C | 21.9°C | 193 mm | 79% | 1.8 m/s | 5.3 |
| 2022 | 30.9°C | 27.6°C | 24.4°C | 35.5°C | 17.0°C | 288 mm | 82% | 2.1 m/s | 5 |
| 2021 | 30.0°C | 27.0°C | 23.9°C | 31.7°C | 21.6°C | 155 mm | 83% | 1.7 m/s | 5.2 |
| 2020 | 29.9°C | 27.2°C | 24.5°C | 32.6°C | 20.9°C | 172 mm | 86% | 2.3 m/s | 5 |
| 2019 | 30.3°C | 27.3°C | 24.2°C | 32.4°C | 22.1°C | 68 mm | 80% | 3.6 m/s | 5.4 |
| 2018 | 30.2°C | 27.5°C | 24.7°C | 32.5°C | 23.0°C | 92 mm | 84% | 2 m/s | 5.3 |
| 2017 🌧️ | 30.3°C | 27.4°C | 24.5°C | 32.0°C | 22.2°C | 326 mm | 84% | 2.6 m/s | 5 |
| 2016 | 30.3°C | 27.4°C | 24.6°C | 32.2°C | 23.0°C | 185 mm | 84% | 1.7 m/s | 5.1 |
| 2015 | 30.0°C | 27.3°C | 24.5°C | 32.3°C | 22.1°C | 179 mm | 84% | 1.5 m/s | 4.7 |
| 2014 | 29.8°C | 27.0°C | 24.1°C | 32.3°C | 22.3°C | 236 mm | 83% | 1.7 m/s | 4.7 |
| 2013 | 29.5°C | 26.7°C | 23.8°C | 31.1°C | 21.6°C | 159 mm | 83% | 1.9 m/s | 4.8 |
| 2012 | 29.3°C | 26.4°C | 23.5°C | 31.5°C | 21.7°C | 151 mm | 84% | 2 m/s | 5 |
| 2011 | 30.2°C | 27.2°C | 24.1°C | 31.5°C | 21.7°C | 132 mm | 82% | 1.9 m/s | 5.2 |
| 2010 | 31.2°C | 27.9°C | 24.6°C | 34.0°C | 20.6°C | 137 mm | 77% | 2.5 m/s | 5.3 |
| 2009 | 29.9°C | 27.1°C | 24.3°C | 31.1°C | 19.5°C | 149 mm | 83% | 1.7 m/s | 5.2 |
| 2008 | 29.3°C | 26.6°C | 23.9°C | 31.1°C | 20.3°C | 98 mm | 85% | 2.6 m/s | 5.1 |
| 2007 | 29.8°C | 27.1°C | 24.4°C | 31.8°C | 21.9°C | 169 mm | 83% | 2.1 m/s | 5.1 |
| 2006 | 30.0°C | 26.6°C | 23.2°C | 31.5°C | 17.7°C | 127 mm | 82% | 1.9 m/s | 5.3 |
| 2005 | 29.8°C | 26.9°C | 23.9°C | 31.5°C | 21.6°C | 140 mm | 84% | 2.6 m/s | 4.8 |
| 2004 | 29.2°C | 26.9°C | 24.5°C | 31.4°C | 22.2°C | 324 mm | 86% | 4 m/s | 4.6 |
| 2003 | 29.6°C | 26.8°C | 23.9°C | 31.0°C | 21.9°C | 175 mm | 86% | 2.2 m/s | 4.8 |
| 2002 | 30.1°C | 27.3°C | 24.5°C | 31.5°C | 23.3°C | 128 mm | 86% | 2.1 m/s | 5.1 |
| 2001 | 28.7°C | 26.0°C | 23.3°C | 31.7°C | 18.3°C | 300 mm | 85% | 2.2 m/s | 4.4 |
| 2000 | 30.2°C | 27.2°C | 24.2°C | 32.5°C | 22.7°C | 175 mm | 83% | 2.1 m/s | 5.1 |
| 1999 | 29.6°C | 26.6°C | 23.5°C | 32.3°C | 20.8°C | 216 mm | 84% | 2.6 m/s | 4.8 |
| 1998 | 29.6°C | 27.0°C | 24.4°C | 32.4°C | 22.2°C | 247 mm | 87% | 2.5 m/s | 4.7 |
| 1997 | 29.3°C | 26.4°C | 23.5°C | 31.1°C | 20.7°C | 189 mm | 85% | 2.3 m/s | 5.1 |
| 1996 | 30.1°C | 26.9°C | 23.7°C | 31.8°C | 20.7°C | 107 mm | 81% | 2 m/s | 5.3 |
| 1995 | 29.8°C | 27.0°C | 24.2°C | 31.1°C | 22.0°C | 179 mm | 85% | 1.7 m/s | 5.1 |
| 1994 | 28.5°C | 26.1°C | 23.7°C | 31.5°C | 21.8°C | 249 mm | 87% | 1.9 m/s | 4.4 |
| 1993 | 29.6°C | 26.8°C | 24.0°C | 32.0°C | 21.2°C | 155 mm | 83% | 2 m/s | 5 |
| 1992 | 29.0°C | 26.5°C | 24.0°C | 30.7°C | 22.4°C | 179 mm | 86% | 2 m/s | 4.9 |
| 1991 | 29.4°C | 26.7°C | 23.9°C | 31.5°C | 18.2°C | 148 mm | 84% | 2 m/s | 5 |
| 1990 | 29.6°C | 26.8°C | 24.0°C | 31.6°C | 20.0°C | 182 mm | 82% | 2.1 m/s | 5.2 |
| 1989 | 30.3°C | 27.3°C | 24.3°C | 32.2°C | 21.9°C | 174 mm | 82% | 2.1 m/s | 5.4 |
| 1988 | 30.2°C | 27.2°C | 24.2°C | 31.9°C | 20.4°C | 56 mm | 82% | 2.6 m/s | 4.9 |
| 1987 | 30.6°C | 27.4°C | 24.2°C | 33.5°C | 22.2°C | 175 mm | 79% | 1.6 m/s | 4.8 |
| 1986 | 29.7°C | 26.8°C | 23.8°C | 31.4°C | 22.5°C | 142 mm | 82% | 1.8 m/s | 5.4 |
| 1985 | 28.5°C | 25.9°C | 23.4°C | 30.4°C | 21.7°C | 254 mm | 84% | 2.6 m/s | 4.9 |
| 1984 ❄️ | 28.9°C | 25.9°C | 22.9°C | 31.5°C | 20.7°C | 184 mm | 81% | 3.1 m/s | 4.8 |
| 1983 | 28.9°C | 26.2°C | 23.5°C | 32.0°C | 17.3°C | 120 mm | 84% | 2.2 m/s | — |
| 1982 | 29.1°C | 26.4°C | 23.6°C | 31.8°C | 20.1°C | 173 mm | 84% | 2 m/s | — |
| 1981 | 29.2°C | 26.2°C | 23.2°C | 31.0°C | 19.0°C | 155 mm | 82% | 2 m/s | — |
Actual recorded September data for each year, 1981–2025 — sourced from NASA POWER.
The average high in September is around 29.8°C with lows near 24.1°C (mean 27°C), based on 45 years of NASA POWER data.
September averages 175 mm of rainfall in Port Saint Lucie, a relatively wet time of year. The wettest on record was 326 mm in 2017.
The hottest September reached 35.5°C in 2022. The coldest dipped to 17°C in 2022.
Comparing the earliest years on record (1981–1985) with the most recent (2021–2025), average September temperatures have risen by about 1.6°C. Daytime highs moved from 28.9°C to 30.8°C and overnight lows from 23.3°C to 24.7°C over the same span.
September is one of the warmer months of the year in Port Saint Lucie and a relatively wet time of year, so plan for around 29.8°C daytime highs and 24.1°C at night.
Not quite — September is the 9th coolest month in Port Saint Lucie, averaging 27°C.
For September in Port Saint Lucie, pack light layers you can adjust through the day, with typical highs of 29.8°C and lows of 24.1°C. Bring an umbrella or light rain jacket too.
Relative humidity in September averages 83% — quite humid.
Average wind speed in September is 2.2 m/s. The windiest September on record averaged 4 m/s (2004).
The wettest September on record was 2017 with 326 mm. On average, September sees 175 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 Port Saint Lucie 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.
