Weather in Split in September

Prime time. If you get to pick your dates, September is the one. Highs average 25.3 °C, lows 18.8 °C, and rain falls on 9 days — nothing in the month is working against you.

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

Rain on 9 days, 3 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 32.9 °C and the coldest night fell to 11.1 °C, and the wettest single day dropped 83 mm — roughly 92% of the month's rain in one day.

September is moderately variable: 21 mm in the driest year against 237 mm in the wettest, around an average of 90 mm. Roughly two Septembers in three land near that average, and the third does something else entirely.

Wind is light at 10.3 km/h, so the temperature on the page is close to the temperature on your skin, and humidity is unremarkable at 65%.

How September sits in the year

The month is on the way down: 4.8 °C cooler than August, with October dropping another 4.4 °C. The first week and the last are not the same trip.

Daylight in September

12.6 hours of daylight, losing 1.5 hours across the month. That is between Split's extremes of 15.4 and 9 hours, so days are long enough not to constrain the plan.

An inland climate

Despite being inland, the year stays fairly even: 23.8 °C between the year's warmest afternoons and coldest nights.

How busy it gets

Peak season. Expect the highest prices of the year and to be booking well ahead.

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

September in Split versus nearby

If Split is one option among several, the nearby comparison is worth making. Dubrovnik is close enough to be a coin toss — within a degree on temperature, the same number of rain days. Slavonski Brod is close enough to be a coin toss — within a degree on temperature, 1 day more rain.

So: September is effectively as good as it gets here — 3 points behind June, which is inside the margin where the weather stops being the deciding factor and price starts being it.

Every month in Split

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