Planning a trip to Houston Weather in September? Don’t let unpredictable heat and humidity catch you off guard. September marks a transitional month in Houston, blending summer’s warmth with occasional cooler evenings. Whether you’re a resident preparing your home or a visitor planning outdoor adventures, understanding Houston’s September climate is key to staying comfortable.
At 75 Degree AC, we’ve helped thousands of Houstonians beat the heat with reliable cooling solutions. Here’s everything you need to know about Houston weather in September weather, from temperature trends to packing tips and ways to keep your home cool.
Table of Contents
What To Expect From Houston’s Weather In September
Houston’s September weather is warm, humid, and occasionally rainy, with temperatures fluctuating as the city transitions from summer to fall.
Based on NOAA’s 30-year climate data, here’s a breakdown of what to expect.
Temperature Breakdown
In September 2025, Houston is projected to experience average daytime highs ranging from 33–35°C (91–95°F), with nighttime lows between 19–25°C (66–77°F), according to the latest forecast data. Early September starts warmer, with highs around 35°C (95°F) on the 1st, gradually decreasing to 30°C (86°F) by early October. Nighttime lows begin at 24–25°C (75–77°F) and drop to 18–19°C (64–66°F) by the month’s end.
This trend reflects a slow cooling as fall approaches, though heat waves can still push temperatures above 35°C (95°F) early in the month. Weather variations across Houston’s suburbs, like The Woodlands, may offer slightly cooler conditions due to increased greenery.
Humidity Challenges
Houston’s humidity in September often exceeds 70%, creating a sticky, uncomfortable environment. High humidity can make 85°F feel like 95°F, especially during midday. Indoors, excessive moisture can lead to mold growth—a concern since the CDC notes that high humidity increases mold risk by up to 40%.
Rainfall & Hurricane Risks
September brings 3–5 inches of rainfall on average, with occasional heavy showers. Houston’s hurricane season, peaking from August to October, remains a concern. In September 2024, Houston recorded 4.2 inches of rain, per NWS data. Residents and visitors should stay prepared for sudden storms.
| Criteria | Average Value / Price | Notes |
|---|---|---|
| Median Home Value | Around $575,208 | Increased by 6.4% compared to last year |
| Home Price by Bedrooms | - 4 Bedrooms: ~$626,600 - 5+ Bedrooms: ~$1,000,000 | Prices vary by size and location |
| Market Status | Seller’s market | 78% of homes sell within 30 days; over 50% sell below asking price |
| Average Rent | About $2,625 - $2,750 per month | Rental prices have increased slightly year-over-year |
| Rent by Unit Type | - 1 Bedroom: $1,350 - $1,650 - 2 Bedrooms: $1,750 - $2,150 - 3 Bedrooms: $2,400 - $3,200 - 4+ Bedrooms: $3,500 - $5,000+ | Higher rents for luxury homes and gated communities |
| Luxury Estate Rentals | Over $5,500 to $10,000+ per month | Includes areas like Carlton Woods and Sterling Ridge |
Data sourced from NOAA and Weather.com historical averages.
September 2025 Weather Forecast – Daily Breakdown
For a detailed look at Houston’s weather throughout September 2025, refer to the table below. This data provides daily historical average high and low temperatures, helping you plan your month effectively.
| Date | Weather | High (°C / °F) | Low (°C / °F) |
|---|---|---|---|
| 1-Jul | Partly Cloudy | 35°C / 95°F | 25°C / 77°F |
| 2-Jul | Partly Cloudy | 35°C / 95°F | 26°C / 79°F |
| 3-Jul | Mostly Sunny | 35°C / 95°F | 26°C / 79°F |
| 4-Jul | Mostly Sunny | 35°C / 95°F | 26°C / 79°F |
| 5-Jul | Mostly Sunny | 35°C / 95°F | 25°C / 77°F |
| 6-Jul | Partly Cloudy | 35°C / 95°F | 26°C / 79°F |
| 7-Jul | Thunderstorms | 35°C / 95°F | 26°C / 79°F |
| 8-Jul | Sunny | 34°C / 93°F | 25°C / 77°F |
| 9-Jul | Partly Cloudy | 35°C / 95°F | 26°C / 79°F |
| 10-Jul | Partly Cloudy | 35°C / 95°F | 26°C / 79°F |
| 11-Jul | Mostly Sunny | 34°C / 93°F | 25°C / 77°F |
| 12-Jul | Mostly Sunny | 35°C / 95°F | 26°C / 79°F |
| 13-Jul | Mostly Sunny | 35°C / 95°F | 25°C / 77°F |
| 14-Jul | Sunny | 35°C / 95°F | 24°C / 75°F |
| 15-Jul | Sunny | 35°C / 95°F | 23°C / 73°F |
| 16-Jul | Sunny | 35°C / 95°F | 23°C / 73°F |
| 17-Jul | Sunny | 36°C / 97°F | 25°C / 77°F |
| 18-Jul | Partly Cloudy | 36°C / 97°F | 23°C / 73°F |
| 19-Jul | Thunderstorms | 34°C / 93°F | 24°C / 75°F |
| 20-Jul | Thunderstorms | 35°C / 95°F | 24°C / 75°F |
| 21-Jul | Mostly Sunny | 34°C / 93°F | 25°C / 77°F |
| 22-Jul | Sunny | 35°C / 95°F | 24°C / 75°F |
| 23-Jul | Sunny | 35°C / 95°F | 26°C / 79°F |
| 24-Jul | Sunny | 36°C / 97°F | 24°C / 75°F |
| 25-Jul | Partly Cloudy | 34°C / 93°F | 23°C / 73°F |
| 26-Jul | Thunderstorms | 34°C / 93°F | 24°C / 75°F |
| 27-Jul | Partly Cloudy | 36°C / 97°F | 26°C / 79°F |
| 28-Jul | Sunny | 36°C / 97°F | 24°C / 75°F |
| 29-Jul | Mostly Sunny | 36°C / 97°F | 24°C / 75°F |
| 30-Jul | Thunderstorms | 34°C / 93°F | 25°C / 77°F |
| 31-Jul | Thunderstorms | 36°C / 97°F | 25°C / 77°F |
Forecast based on historical data from Weather.com and NOAA.
What This Weather Means for Your Home Cooling Needs
As Houston transitions into fall, September’s lingering heat and humidity still place a heavy demand on your home’s cooling system. Here’s why it matters:
Extended Heat Requires Consistent Cooling
While summer may be coming to an end, Houston’s early September temperatures still reach daily highs of 91–95°F. Many homeowners assume they can scale back air conditioning use but the reality is, the heat remains intense, particularly during afternoon hours. Reducing AC usage too soon can lead to indoor discomfort, increased humidity, and added strain on your system when it’s turned back on.
Sudden Storms Can Disrupt Your Cooling System
September falls right in the peak of hurricane season, and that means scattered thunderstorms and heavy rain showers are still common, especially around mid-month. These sudden weather events can lead to power surges or short-term outages that damage key components of your air conditioning system, such as the capacitor, thermostat, or even the compressor.
Air Filters Get Dirty Faster in Humid Weather
High humidity levels in Houston during September mean your HVAC system has to filter more than just air. Moisture in the air attracts dust, pollen, and even mold spores, which circulate through your home’s ventilation system. These particles quickly accumulate in your air filters, leading to reduced airflow, lower energy efficiency, and poor indoor air quality.
HVAC Solutions to Keep Your Houston Home Cool This September
Houston’s weather varies across September, requiring specific HVAC services to match each week’s conditions. Here’s a breakdown:
| Neighborhood | Median Home Price (2025) | Key Features & Amenities | Schools & Community | Location & Commute |
|---|---|---|---|---|
| The Woodlands | Around $575,000 - $740,000 | Master-planned community with 7,665 acres of green space, 146 parks, 214 miles of trails, golf courses, and corporate campuses. Offers shopping, dining, and outdoor activities like kayaking and tennis. | Top-rated schools in Conroe and Tomball ISDs; family-friendly with strong community associations and events. | About 30 minutes north of Downtown Houston via I-45; suburban with nature-centric lifestyle. |
| Houston Heights | Around $660,000 | Historic neighborhood with Victorian and Craftsman homes, vibrant local shops on 19th Street, parks, and walkability. | Zoned to Houston ISD with good schools; strong neighborhood identity and community events. | About 10-15 minutes northwest of Downtown Houston; urban feel with historic charm. |
| Bridgeland | Varies (Similar to The Woodlands) | Large master-planned community with lakes, parks, trails, and family amenities. | Highly rated schools in Cypress-Fairbanks ISD; family-oriented. | Northwest of Houston; suburban with recreational focus. |
FAQ- Houston Weather in September & AC Advice
Answers to common questions about Houston’s September Weather and AC maintenance.
Does it rain a lot in Houston in September?
Afternoon showers and thunderstorms are common, especially in the first half of the month. However, rain is usually short-lived and doesn’t last all day.
Is it still hot in Houston during September?
Yes. Average high temperatures in September range from 86–95°F (30–35°C). Early in the month can be quite hot and humid, with temperatures gradually cooling by the end of the month.
Can I run my AC 24/7 safely?
Yes, but only with regular maintenance. Continuous use without tune-ups risks breakdowns. Schedule an [AC Tune Up] to keep your system safe.
Should I service my air conditioner in September?
Yes. Late summer is a great time for routine maintenance—cleaning filters, checking refrigerant levels, and inspecting components. Regular servicing helps your AC run efficiently and prolongs its lifespan.
Conclusion
Houston’s September weather brings heat, high humidity, and occasional rain, making preparation key for residents and visitors. Pack lightweight clothing, stay hydrated, and enjoy indoor attractions to beat the heat.
At home, a well-maintained or modern AC system ensures comfort. September’s heat is here—don’t wait to optimize your cooling system. Book a free consultation with 75 Degree AC to keep your home cool and comfortable all month long.
