Weather in Atlanta in September

A good month. September works. It is not the peak, but nothing about it fights you. Highs average 29.7 °C, lows 17.3 °C, and rain falls on 9 days — nothing in the month is working against you.

September ranks 6 of 12 in Atlanta: past the worst of the year but short of October, which is the month to book if the dates are open.

Rain on 9 days, 3 of them heavy. Enough to need a plan B, not enough to need a plan around it. Pack for 29.7 °C days and 17.3 °C nights; the spread matters more here than any single number.

What the averages hide

Averages flatten a month, and this one hides a few things: 15 days top 30 °C — hot spells arrive, but they break. Across the twenty years measured, the hottest September day reached 39 °C and the coldest night fell to 5.4 °C, and the wettest single day dropped 95 mm — roughly 103% of the month's rain in one day.

September is moderately variable: 11 mm in the driest year against 282 mm in the wettest, around an average of 92 mm. Roughly two Septembers in three land near that average, and the third does something else entirely.

Wind is light at 4.2 km/h, so the temperature on the page is close to the temperature on your skin, and humidity is unremarkable at 70%.

How September sits in the year

The month is on the way down: 2.8 °C cooler than August, with October dropping another 5.6 °C. The first week and the last are not the same trip. Rain has already shifted: 7 days fewer than August had.

Daylight in September

12.4 hours of daylight, losing 1 hours across the month. That is between Atlanta's extremes of 14.4 and 9.9 hours, so days are long enough not to constrain the plan.

An inland climate

With no coast nearby, the year swings a fair way — 32.8 °C between the warmest afternoons and the coldest nights, wider than any coastal city at this latitude would manage.

How busy it gets

Shoulder. The value months — prices ease off and you get the place closer to itself.

Crowd levels are estimated from climate desirability and school-holiday calendars, not from visitor numbers.

September in Atlanta versus nearby

If Atlanta is one option among several, the nearby comparison is worth making. Huntsville is close enough to be a coin toss — within a degree on temperature, the same number of rain days. Montgomery is close enough to be a coin toss — within a degree on temperature, the same number of rain days.

So: September works, with October the better month by 17 points if the dates can move. If they cannot, nothing here should stop you booking.

Every month in Atlanta

See all twelve months in Atlanta, or where else to go in September.