Atlanta September Weather: What to Expect and How to Plan Your Month

September in Atlanta is a transition month. Summer heat is still hanging on, but hints of fall start to show up—especially later in the month. If you live in Atlanta, are planning a visit, or are scheduling an event, it helps to know what September weather usually brings and how it can affect your day-to-day plans.

Overall Climate in Atlanta in September

September is typically:

• Warm to hot, especially in the first half of the month
• Humid, but usually not as oppressive as July and August
• Stormy at times, with scattered showers and the occasional thunderstorm
• Gradually cooling as you move toward late September and early October

In short, you’re unlikely to need a jacket most days, but you will want breathable clothing and a flexible plan in case of rain.

Typical Temperatures in Atlanta in September

While day-to-day weather can vary, September temperatures in Atlanta usually sit in a comfortable—but often still summery—range.

Average Temperature Range

Early in September, temperatures often resemble late summer, with some days edging into the upper 80s. By the end of the month, afternoons tend to feel more like early fall, especially if a cool front moves through.

Humidity and “Feels Like” Heat

Atlanta’s September humidity remains noticeable, especially in the first half of the month.

• Humidity: Often moderate to high, especially after rain or in the morning
• Heat index: On warmer days, it can feel a few degrees warmer than the actual air temperature
• Indoor vs. outdoor comfort: Air conditioning is still widely used in homes, businesses, and public buildings

If you’re spending time outside—walking the BeltLine, exploring Piedmont Park, or attending a game at Mercedes-Benz Stadium—expect it to feel warmer in direct sun and plan breaks in shade or air-conditioned spaces.

Rain, Storms, and Hurricane Season Impacts

September is an active weather month for rain and storms in the Atlanta area.

Rain Patterns

• Scattered showers and thunderstorms are common, often in the afternoon or early evening
• Rain can range from brief downpours to heavier storms with lightning
• Many days are still mostly dry, but fast-changing conditions are normal

Keeping a compact umbrella or lightweight rain jacket handy is wise, especially if you walk or take MARTA.

Hurricane Season Effects

While Atlanta is well inland, Atlantic hurricane season can indirectly influence September weather:

• Remnants of tropical systems can bring periods of heavy rain and gusty winds
• Travel plans (especially flights in and out of Hartsfield-Jackson Atlanta International Airport) can be affected by weather elsewhere in the Southeast
• Localized flooding may occur in low-lying or poor-drainage areas when extended rain bands move through

For updated local alerts, Atlanta residents and visitors can monitor:

• National Weather Service – Peachtree City Office (covers metro Atlanta)
  • 4 Falcon Drive, Peachtree City, GA 30269
  • Recorded forecast line is typically available via local phone listings or online weather sources

Sunshine, Cloud Cover, and Air Quality

September usually offers a good mix of sun and clouds in Atlanta.

• You can expect many partly sunny days, especially between passing showers
• UV levels can still be high, so sun protection (hat, sunscreen, sunglasses) remains useful
• Air quality is often moderate to good, though some days can be hazier, especially during warm, stagnant periods

If you’re sensitive to air quality, you can routinely check local conditions through regional air monitoring services or weather providers that cover the Atlanta metro.

What to Wear in Atlanta in September

Planning your wardrobe around September weather in Atlanta is mostly about staying cool and adaptable.

Everyday Clothing

For most days, you’ll be comfortable in:

• Lightweight tops: cotton or breathable blends
• Shorts, skirts, or lightweight pants
• Comfortable walking shoes or sandals
• Light layers (like a thin cardigan or long-sleeve shirt) for air-conditioned interiors

You typically do not need heavy jackets or coats. A light sweater is sometimes helpful for cooler late nights, especially toward the end of the month.

Rain and Sun Preparedness

• 🌦️ Carry a small umbrella or packable rain jacket if you’ll be out all day
• 🧢 Hat and sunglasses help with strong afternoon sun
• 🧴 Sunscreen is worth using if you’ll be outdoors at festivals, parks, or sporting events

Outdoor Activities and Events in September

September is a popular month for outdoor events in Atlanta because conditions are still summer-like but slowly becoming more comfortable.

Parks, Trails, and Green Spaces

With warm temperatures and frequent sunshine, this is a great time to:

• Walk or bike the Atlanta BeltLine
• Spend a day at Piedmont Park, Grant Park, or Chastain Park
• Visit attractions like the Atlanta Botanical Garden or Zoo Atlanta

Just remember:

• Midday can still be quite hot, so mornings and late afternoons are more comfortable for long walks or runs
• Afternoon pop-up thunderstorms can appear, so check the forecast if you plan picnics or gatherings

Sports and Stadiums

Atlanta’s sports calendar is active in September:

• Football season kicks off, with games at Mercedes-Benz Stadium and nearby college campuses
• Baseball may still be in regular season at Truist Park in nearby Cumberland

Most larger venues are indoors or partially covered, but tailgating, walking to and from MARTA, or exploring nearby neighborhoods will still put you in warm, sometimes humid conditions.

Travel Planning: Flights, Driving, and Getting Around

Flying Into or Out of Atlanta

Hartsfield-Jackson Atlanta International Airport is busy year-round. In September:

• Thunderstorms can cause delays, especially during the afternoon and evening
• Remnants of tropical systems in the Southeast may indirectly affect schedules

Build in a bit of time buffer if you have connecting flights, and check forecasts and airline alerts on travel days.

Driving Around the City

Road conditions are usually good, but:

• Heavy downpours can lead to temporary ponding or minor flooding on some streets
• Visibility can drop quickly in intense showers
• Late-day storms can coincide with rush hour traffic, slowing commutes on interstates like I-75, I-85, and I-285

If you’re not familiar with Atlanta roads, allow extra time in the schedule on days with rain in the forecast.

How September Compares to Other Months in Atlanta

To put September weather into local context:

• Compared to July and August:

  • Still warm and humid, but often slightly less intense
  • Fewer extremely hot days, especially late in the month

• Compared to October:

  • September is noticeably warmer and more humid
  • October brings more distinct fall-like days and cooler nights

If you’re deciding between visiting in late September or October, September gives more of a late-summer feel, while October leans more toward true fall.

Tips for Staying Comfortable and Prepared

A few simple habits go a long way during Atlanta’s September weather:

• Check the daily forecast before committing to all-day outdoor plans
• Hydrate, especially if you’re walking the city, visiting attractions, or attending outdoor events
• Plan strenuous activities (running, hiking, yard work) for morning or early evening when it’s cooler
• Keep rain gear handy if you’ll be far from your car or hotel during the afternoon
• Remember that many indoor attractions—like museums, the Georgia Aquarium, and major shopping centers—are air-conditioned, making them good backup options if storms roll in

Local Resources for Weather Information

For Atlanta-specific weather updates, watches, and warnings, residents and visitors commonly rely on a mix of local and national sources. Two key official resources include:

• National Weather Service – Peachtree City (Atlanta Metro Coverage)

  • Address: 4 Falcon Drive, Peachtree City, GA 30269
  • Provides official forecasts, advisories, and severe weather alerts for the Atlanta region

• City of Atlanta – Office of Emergency Preparedness

  • Many residents monitor city-wide emergency communications for major weather-related impacts, such as flooding or significant storm damage

These resources are especially useful during weeks when tropical systems or strong storm fronts may influence metro Atlanta.

Knowing how Atlanta weather in September usually behaves makes it easier to pack, schedule events, and move through daily life comfortably. Expect mostly warm, often humid days, a real chance of passing showers or storms, and the first subtle signs that fall is on the way.