Atlanta Weather in September: What to Expect and How to Plan

September in Atlanta, Georgia is a true transition month. Summer’s heat starts to ease, but the city still feels warm, humid, and occasionally stormy. If you live in Atlanta—or you’re visiting for a game, a festival, or a work trip—knowing what September weather is really like can help you pack smart, plan outdoor time, and avoid surprises.

Atlanta Weather in September at a Glance

September in Atlanta is best described as late summer sliding into early fall.

Here’s a quick overview:

You’ll feel that it’s still summer-like, especially around Labor Day, but by late September mornings and evenings can start to feel noticeably more comfortable.

Temperature: How Hot Does Atlanta Get in September?

Daytime highs

• Early September: Many days reach the mid to upper 80s°F.
• Mid to late September: Highs more often fall in the low 80s°F, with some cooler days mixed in.

Short heat spikes can still push temperatures close to 90°F, especially the first half of the month, so plan for warm-weather clothing: light shirts, shorts, and breathable fabrics.

Nighttime lows

• Typical lows sit around the mid 60s°F.
• Some nights, especially later in the month, may dip into the low 60s°F.

Evenings are often pleasant for outdoor dining, walks on the BeltLine, or catching a game at Truist Park or Mercedes-Benz Stadium, but you might want a light layer if you run cold.

Humidity and “Feels Like” Temperatures

Humidity remains a major factor in Atlanta weather in September, particularly during the first half of the month.

• Expect muggy mornings with a sticky feel, especially after overnight rain.
• Afternoon temperatures in the 80s can feel hotter if humidity is high.
• Later in the month, some days will feel less oppressive, with lower humidity and a more comfortable warmth.

If you’re spending long periods outside—walking the Atlanta BeltLine, exploring Piedmont Park, or attending festivals—plan for:

• Light, breathable clothing
• A hat and sunglasses
• Regular water breaks, especially in the afternoon

Rain, Storms, and Tropical Influences

Typical September rain pattern

September is part of Atlanta’s late-summer storm season. While not the rainiest month, it can bring:

• Scattered afternoon thunderstorms, often short but intense
• Heavy downpours on some days, followed by sunshine
• Stretches of dry, sunny days in between

Thunderstorms often form in the afternoon to early evening, so morning activities are frequently less affected.

Tropical systems

Because Atlanta sits inland but still within reach of Gulf and Atlantic weather, remnants of tropical storms or hurricanes can sometimes:

• Bring bands of rain and gusty winds
• Create very soggy days with off-and-on showers

These events do not happen every year, but they’re common enough that it’s wise to keep an eye on forecasts if a named storm is in the news during your visit.

Sunshine, Clouds, and Daylight

• Sunrise: Roughly around 7:10–7:25 a.m. by mid to late September
• Sunset: Around 7:45 p.m. early in the month, shifting to about 7:15 p.m. later

You get plenty of usable daylight for outdoor activities.

Sky conditions vary from:

• Sunny and mostly clear days (great for parks and patios)
• Partly cloudy, hazy afternoons
• Days with build-up of afternoon storm clouds

Sunscreen is still important; the sun angle is a bit lower than July, but UV exposure can still be strong, especially in the middle of the day.

What to Pack for Atlanta in September

If you’re visiting—or just refreshing your wardrobe—focus on flexibility. September can swing from hot and sticky to mild and breezy.

Clothing essentials

• Short-sleeve shirts / light tops – Main daytime uniform
• Shorts, skirts, or light pants – Breathable materials work best
• Lightweight long-sleeve layer or cardigan – For cooler evenings or strong indoor air conditioning
• Comfortable walking shoes or breathable sneakers – Sidewalks and paths can be hot underfoot
• Rain-resistant jacket or compact umbrella – Handy for passing thunderstorms

Accessories and extras

• Sunglasses and a hat – Useful for bright afternoons in open areas like Piedmont Park
• Small umbrella or poncho – Especially if you’ll rely on walking or transit
• Refillable water bottle – Easy to keep hydrated when you’re out at festivals, markets, or parks

If you’re attending a more formal event (weddings, conferences), consider lightweight dress clothes—Atlanta’s heat and humidity can make heavy fabrics uncomfortable.

Outdoor Plans: What Atlanta Weather in September Means for Activities

September is often a great month for outdoor events in Atlanta, with many local favorites scheduled this time of year.

Festivals and events

You’ll frequently find:

• Neighborhood festivals in areas like Grant Park, Inman Park, or Midtown
• Food and arts events in Piedmont Park and along the Atlanta BeltLine
• College and professional football games that bring crowds outdoors

Plan to:

• Schedule more active outdoor time (walking, biking, exploring) in the morning.
• Expect warm, possibly humid afternoons, especially early September.
• Bring something for shade and sun protection if you’ll be in open areas for long periods.

Parks, trails, and outdoor spaces

Popular spots like:

• Piedmont Park
• Atlanta BeltLine Eastside Trail
• Chastain Park
• Stone Mountain Park (east of the city)

are often busy in September. Conditions are usually:

• Warm enough for short sleeves all day
• Comfortable for evening walks and outdoor concerts
• Occasionally interrupted by brief, heavy showers

Check the hour-by-hour forecast if you’re planning activities like hiking, outdoor concerts, or long bike rides.

Driving, Walking, and Commuting in September Weather

Driving

• Sudden thunderstorms and heavy downpours can reduce visibility on highways like I-75, I-85, and I-285.
• Roads can become slick after the first rain following a dry stretch.
• Afternoon storms can line up with rush hour, extending drive times.

It’s smart to allow a little extra travel time when the forecast mentions storms.

Walking and transit

If you’re using MARTA, walking between stations, or exploring neighborhoods:

• Heat and humidity can make midday walks feel more intense.
• Sidewalks can puddle quickly in heavy rain.
• Light rain gear and comfortable shoes are very helpful.

Areas around Downtown, Midtown, and Buckhead are all walkable in parts, but shade is not guaranteed, so plan accordingly.

Air Quality and Allergies

Air quality

On many days, air quality in Atlanta during September is acceptable for most people, but occasionally:

• Hot, stagnant days can bring haze and higher pollution levels.
• Those sensitive to air quality may want to check daily conditions before intensive outdoor exercise.

Allergies

Late summer and early fall can be bothersome for some allergy sufferers, especially with:

• Ragweed and other weed pollens
• Residual mold spores after rain and in humid conditions

If you’re sensitive, it can help to:

• Check daily pollen and air quality forecasts for Atlanta
• Plan intense outdoor activity for lower-pollen times, often earlier in the day after rain has cleared the air

For personalized medical guidance, local residents can consult healthcare providers in the Atlanta area; this overview is informational only.

Weather Resources and Local Contacts

If you live in Atlanta or are staying for a while, you can track September weather and alerts through:

• City of Atlanta emergency information:
  Atlanta City Hall
  55 Trinity Ave SW
  Atlanta, GA 30303
  Main information line: (404) 330-6000

• DeKalb and Fulton County emergency management offices (for county-level alerts and preparedness resources)

These agencies share information during significant weather events, such as tropical system remnants or severe storms that may impact the city.

Practical Tips for Enjoying Atlanta in September

Here are some simple ways to stay comfortable and prepared:

• ☀️ Plan outdoor activities earlier or later in the day to avoid peak heat and humidity.
• 🌧️ Check the daily forecast before heading out, especially in the afternoon when storms are most likely.
• 🧴 Use sunscreen and bring water, even if the temperature doesn’t seem extreme.
• 👟 Wear breathable clothing and comfortable shoes if you’ll be walking or standing outside for long events.
• ☔ Carry a small umbrella or packable rain jacket—you may not need it every day, but you’ll be glad to have it when storms pop up.

Understanding Atlanta weather in September helps you make the most of this in-between season: warm enough for summer-style plans, with just enough hints of fall to make evenings especially enjoyable.