Atlanta weather and climate guide

7-day forecast for Atlanta

Tonight in Atlanta, GA brings slight chance showers and thunderstorms then partly cloudy. Across the 8-day outlook, highs average 96°F and lows average 77°F, ranging from 76°F to 97°F. No day in the period shows a meaningful chance of precipitation.

Current conditions

Observed at Atlanta, Hartsfield - Jackson Atlanta International Airport (KATL) at 8:35 PM EDT.

Elevation makes Atlanta milder than its latitude

At roughly 1,050 feet, Atlanta is one of the highest large cities in the eastern United States, and that elevation is worth several degrees. Summer highs average 89 °F in July, meaningfully cooler than Savannah or Macon at similar latitude but near sea level.

The Appalachian foothills also give the city a genuine transition-season character. Fall color arrives in the northern suburbs and the mountains an hour north, and spring comes in stages rather than all at once. Winter produces real cold snaps that the coastal plain does not see.

Humidity is still substantial — dew points in the low 70s through summer — but the combination of slightly lower temperature and afternoon thunderstorm cooling makes Atlanta summers more tolerable than those in Houston or New Orleans. Heat index above 100 is common; above 110 is rare.

Pollen season is a genuine weather story

Atlanta has one of the highest pollen burdens of any American city, and it is a direct consequence of the tree canopy. The metro area is among the most heavily forested large cities in the country, dominated by oak and pine — both wind-pollinated species that release enormous quantities of pollen.

The season starts in February with elm and maple, peaks brutally from late March through April with oak and pine, then shifts to grasses in May and June and ragweed in late summer. Peak-day counts in April routinely exceed the extremely-high threshold by an order of magnitude, and the visible yellow film on cars in April is pine pollen, which is large, highly visible and actually less allergenic than the invisible oak pollen causing most of the symptoms.

Weather drives it directly. Dry, warm, breezy days send counts soaring; a sustained rain washes the air clean for a day or two before release resumes. If you have allergies, the rain forecast in April is more relevant to your day than the temperature.

Ice, not snow, is the winter hazard

Atlanta averages about two inches of snow a year and often gets none. What it does get, every few winters, is freezing rain or a snow event that arrives at exactly the wrong time — and the metro area handles it very badly.

The reasons are structural rather than meteorological. The region has a small fleet of treatment equipment relative to its road mileage, because equipment that sits unused for four years out of five is hard to justify. Drivers have little practice. Traffic volumes on the interstates are enormous. And the terrain is genuinely hilly, so even a thin glaze immobilizes vehicles on grades.

The January 2014 event is the standard example: roughly two inches of snow arriving midday, with schools and businesses releasing simultaneously, produced gridlock that stranded thousands of people in cars overnight and left children sleeping in schools. The lesson locals took is that the correct response to a winter weather advisory here is to stay home preemptively rather than to leave early.

Freezing rain is the worse hazard of the two. A quarter inch of ice accretion brings down pine limbs across power lines, and the region's combination of tall pines and overhead distribution makes multi-day outages likely.

Severe weather and Dixie Alley

Atlanta sits within the region sometimes called Dixie Alley, and Southeast tornadoes differ from Great Plains tornadoes in ways that make them more dangerous per event.

They are more likely to occur at night, when people are asleep and unable to see them. They are frequently wrapped in heavy rain and low cloud, so visual confirmation is often impossible. The tree canopy blocks sightlines. And the region has a high density of manufactured housing, which offers little protection. The peak season is March through May, with a secondary uptick in November.

An EF2 tornado struck downtown Atlanta in March 2008, damaging the Georgia Dome during an SEC tournament game and breaking windows in high-rises — a reminder that urban cores are not protected by their buildings.

The practical consequence is that a NOAA Weather Radio or a phone alert that will wake you matters more here than in Oklahoma. Relying on seeing the storm is not a workable strategy in the Southeast.

Inland tropical rainfall

Atlanta is roughly 250 miles from the Atlantic and 300 from the Gulf, which means it is not a wind-damage city for tropical systems but is very much a rainfall city. Storms that make landfall on the Gulf Coast frequently track northeast and dump six to ten inches of rain on north Georgia as they decay.

The terrain matters here. Creeks in the metro area drain small, steep, heavily paved basins, and they rise very fast. Flash flood warnings during a decaying tropical system deserve to be taken as seriously as they would be on the coast.

September 2009 brought a non-tropical but comparable event, when a stalled system produced over twenty inches in parts of the western metro area, killed ten people and caused catastrophic flooding along the Chattahoochee tributaries. That storm is the reason many local floodplain maps were revised.

Weather hazards to know about

• Ice storms and freezing rain

  December through February

  Small amounts cause outsized disruption. Ice on pines takes down power lines; ice on hills immobilizes traffic across the metro area.

• Nocturnal and rain-wrapped tornadoes

  March through May, with a November secondary season

  Dixie Alley storms are often invisible and often overnight. An alerting method that wakes you is essential.

• Flash flooding

  Year-round, worst with decaying tropical systems

  Steep, paved urban creek basins rise within an hour of heavy rain.

• Humid heat

  June through September

  Heat index above 100 is routine. Elevation and afternoon storms keep it below Gulf Coast extremes.

• Extreme pollen

  February through June, peaking in April

  Among the highest tree pollen counts in the country, driven by an oak and pine canopy. Dry, windy days are the worst.

What to wear and pack, by season

Spring (March to May)

Light layers, rain gear, and allergy medication if you are susceptible. Beautiful season with a real cost for allergy sufferers.

Summer (June to September)

Lightweight breathable clothing and a compact rain layer for afternoon thunderstorms that build and pass quickly.

Fall (October to November)

The most reliable season. Light layers, with a jacket needed by mid-November.

Winter (December to February)

A medium coat handles most days. If a winter weather advisory is issued, the useful preparation is food and a charged phone rather than boots.