Weather in Gwangju in September

Prime time. September is about as good as Gwangju gets. Highs average 25.8 °C, lows 16.8 °C, and rain falls on 10 days — nothing in the month is working against you.

September ranks 3 of 12 in Gwangju. Only October scores clearly higher, and the difference is small enough to be settled by price rather than weather.

Rain on 10 days, 4 of them heavy. Enough to need a plan B, not enough to need a plan around it. Nothing specialised needed — this is the month you pack for the trip rather than for the weather.

What the averages hide

The averages here are honest — no hidden extremes worth planning around. Across the twenty years measured, the hottest September day reached 31.3 °C and the coldest night fell to 7.1 °C, and the wettest single day dropped 114 mm — roughly 75% of the month's rain in one day.

September is moderately variable: 31 mm in the driest year against 466 mm in the wettest, around an average of 151 mm. Roughly two Septembers in three land near that average, and the third does something else entirely.

Wind is light at 7 km/h, so the temperature on the page is close to the temperature on your skin, and humidity runs at 84%, high enough to notice on the warm days without dominating them.

How September sits in the year

The month is on the way down: 3.8 °C cooler than August, with October dropping another 5.4 °C. The first week and the last are not the same trip. Rain is the thing that moves: October brings 5 days less of it, so pushing the dates later buys drier weather.

Daylight in September

12.5 hours of daylight, losing 1.1 hours across the month. That is between Gwangju's extremes of 14.5 and 9.8 hours, so days are long enough not to constrain the plan.

Sea temperature

The sea sits at about 25.4 °C in September — warm enough to stay in as long as you like. This is the warmest the water gets all year.

How busy it gets

Busy. Popular without being frantic; book the things you care about, improvise the rest.

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

September in Gwangju versus nearby

If Gwangju is one option among several, the nearby comparison is worth making. Daegu is close enough to be a coin toss — within a degree on temperature, 1 day more rain. Busan is close enough to be a coin toss — within a degree on temperature, 1 day more rain.

So: September works, with October the better month by 11 points if the dates can move. If they cannot, nothing here should stop you booking.

Every month in Gwangju

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