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

September in Atlanta is a transition month: summer heat starts to ease, evenings become more comfortable, and hints of fall begin to show up—without the true chill yet. If you live in Atlanta, plan to visit, or are scheduling events, knowing what Atlanta weather in September is really like can help you dress right, plan better, and stay comfortable.

Overall Weather Pattern in Atlanta in September

September in Atlanta is generally:

• Warm to hot during the day
• Mild to comfortable at night
• Humid, but usually less oppressive than July and August
• Occasionally rainy, with some influence from tropical systems

Typical conditions you can expect:

• High temperatures: Often in the low to mid-80s°F
• Low temperatures: Commonly in the mid-60s°F
• Humidity: Noticeable, especially early in the month
• Rain: Scattered showers and thunderstorms are still possible

For many residents, early September feels like late summer, while late September can feel like early fall.

Temperature: Early September vs. Late September

Atlanta’s September weather doesn’t change overnight, but there is a clear trend from hotter to milder as the month goes on.

Early September (Labor Day time frame)

• Daytime: Still quite summerlike, with highs in the mid-80s°F or even higher on some days.
• Evenings: Often warm and humid; short sleeves are usually fine late into the night.
• Feels-like temperature: Can be higher due to humidity, especially after afternoon showers.

Mid to Late September

• Daytime: Highs usually shift toward the upper 70s to low 80s°F.
• Mornings and evenings: More comfortable, sometimes cool enough for a light layer.
• Humidity: Often begins to ease, so heat feels less heavy even when temperatures are similar.

Key takeaway: If you’re planning outdoor events in Atlanta in September, later in the month usually offers more pleasant, less sticky conditions.

Rain, Storms, and Tropical Influences

September sits within the Atlantic hurricane season, and while Atlanta is inland, the city can still be affected by:

• Remnants of tropical storms or hurricanes
• Increased cloud cover and rain bands
• Occasional gusty winds

Typical Rain Pattern

• Scattered afternoon thunderstorms are still possible, especially early in the month.
• Rain often arrives as short, heavy showers rather than all‑day washouts.
• Tropical systems can sometimes lead to widespread rain over a day or two, but that is not constant every year.

How This Affects Daily Life

• Outdoor plans (festivals, sports, parks) may need backup indoor options.
• Traffic on interstates like I‑75, I‑85, and I‑285 can slow significantly during heavy rain.
• Low-lying or poorly drained areas of the city may see temporary puddling or minor street flooding during downpours.

If you want localized, real-time rain and storm details, the National Weather Service Atlanta office (located in Peachtree City) is a primary official source:

• National Weather Service Forecast Office
  Peachtree City, GA 30269
  Public forecast information is available by phone at (770) 486‑1133 (recorded/office lines; check menu options as they may change).

Humidity and Air Quality

Humidity

• Humidity is still noticeable in September, especially earlier in the month.
• It’s usually less intense than peak summer, but you may still experience:
  • Frizzy hair and sticky clothing
  • A “heavier” feel when walking or exercising outdoors
• Morning hours can feel more humid, particularly after overnight showers.

Air Quality

By September:

• Ozone-related smog days tend to decrease compared to the hottest summer months.
• However, there can still be days with moderate air quality, especially around busy traffic corridors and during stagnant weather patterns.

You can usually find local air quality information through official state and regional sources based in the Atlanta area, such as state environmental agencies and the City of Atlanta’s environmental programs.

Sunrise, Sunset, and Daylight in September

Days get noticeably shorter through the month, which affects commuting, outdoor activities, and event planning.

• Early September:
  • Sunrise: roughly around 7:00 a.m.
  • Sunset: roughly around 8:00 p.m.
• Late September:
  • Sunrise: closer to 7:30 a.m.
  • Sunset: closer to 7:15 p.m.

This shift means:

• Evening outdoor events at places like Piedmont Park, the BeltLine, or Truist Park may begin in daylight but end after dark.
• Morning commutes and early school drop‑offs may begin in dimmer light by the end of the month.

What to Wear in Atlanta in September

Everyday Clothing

Plan for layers more than for major warmth:

• Tops: T‑shirts, light blouses, short sleeves; a light cardigan or thin jacket for late evenings.
• Bottoms: Shorts, skirts, and lightweight pants are usually comfortable.
• Shoes: Breathable sneakers, sandals, or casual shoes suitable for walking on city sidewalks and parks.

For Work and Events

For office buildings and events around Downtown, Midtown, and Buckhead:

• Many indoor spaces run strong air conditioning, so you may want:
  • A light sweater or blazer for meetings or conferences.
  • Closed-toe shoes if you’ll be in cold indoor spaces for long periods.

For Children and Students

If you’re sending kids to school in September (Atlanta Public Schools or surrounding districts):

• Short sleeves are usually fine for recess and after‑school activities.
• Pack a light jacket or hoodie in their backpack for unexpected cooler mornings or air‑conditioned classrooms.

Packing Tips for Visitors to Atlanta in September

If you’re traveling to Atlanta in September, consider this simple checklist:

Clothing:

• ✅ 2–3 pairs of shorts or light pants
• ✅ Several breathable shirts (cotton or moisture‑wicking)
• ✅ One light jacket or sweater
• ✅ Comfortable walking shoes and/or breathable sandals

Weather-related extras:

• ✅ Compact umbrella or light rain jacket
• ✅ Hat and sunglasses for midday sun
• ✅ Small daypack for carrying water and a layer

For outdoor plans at attractions like the Atlanta BeltLine, Zoo Atlanta, or Stone Mountain Park, you may also want:

• Refillable water bottle
• Light cap or visor
• Sunscreen for midday hours

Outdoor Activities and Events in September

September is a popular time in Atlanta for festivals, sports, and outdoor dining because conditions are generally more comfortable than peak summer.

Comfort for Outdoor Activities

You can usually expect:

• Pleasant mornings: Great for walks in Piedmont Park, the Chattahoochee River trails, or the Atlanta Botanical Garden.
• Warm afternoons: Still fine for outdoor patios and festivals, though a bit warm in full sun.
• Comfortable evenings: Ideal for rooftop dining in Midtown or events at outdoor venues around the city.

If you are planning a large event (weddings, corporate outings, or community events) in Atlanta parks or open-air spaces:

• Have a shade plan (tents, canopies, or indoor backup).
• Keep water available for guests, especially older adults and children.
• Monitor official forecasts on the day for potential thunderstorms or tropical rain.

Driving and Commuting in September Weather

Rain in September can create challenges, especially during busy commute times around Downtown Connector (I‑75/85), I‑285, and major surface streets.

What to Expect

• Sudden downpours can lead to:
  • Reduced visibility
  • Slippery roads
  • Slower traffic and longer travel times
• During remnants of tropical systems:
  • Ponding water on some roads
  • Increased risk of minor flooding in low areas

Practical Tips for Atlanta Drivers

• Allow extra commute time on days with rain in the forecast.
• Keep windshield wipers and tire tread in good condition.
• If you must drive during heavy rain, reduce speed and leave extra stopping distance.

Staying Informed About Atlanta Weather in September

For day‑to‑day planning, it helps to check local forecasts specific to your Atlanta neighborhood or suburb (for example, Buckhead, Decatur, College Park, or Sandy Springs), since storms and showers can be spotty.

Key official and public-facing resources in the Atlanta area include:

• National Weather Service (NWS) Atlanta/Peachtree City Office
  – Provides regional forecasts, outlooks, and weather alerts.
  – Phone: (770) 486‑1133 (office/recorded information; menu options may change).

• City of Atlanta emergency and public safety offices
  – Share updates during severe weather, flooding concerns, and city service changes.

You can also rely on local metro Atlanta TV and radio stations for frequent, neighborhood-focused updates and severe weather cut‑ins during active systems.

Quick Reference: Typical Atlanta September Weather at a Glance

In practical terms, Atlanta weather in September is warm, gradually becoming more comfortable, with occasional rain and storms still in the mix. Light, breathable clothing with a simple rain plan will serve you well whether you’re commuting, exploring the city, or planning a special event.