Weather in Graz in September

Prime time. If you get to pick your dates, September is the one. Highs average 21.3 °C, lows 10.6 °C, and rain falls on 11 days — nothing in the month is working against you.

September is the highest-scoring month of the twelve. The nearest rival is May, and the month at the other end of the year is December.

Rain on 11 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

Averages flatten a month, and this one hides a few things: it never really gets hot: not one day in an average September reaches 30 °C. Across the twenty years measured, the hottest September day reached 33.1 °C and the coldest night fell to 1.5 °C, and the wettest single day dropped 45 mm — roughly 47% of the month's rain in one day.

September is statistically steady but not small: the year-to-year variation is modest in relative terms, yet the wettest September on record still delivered 184 mm against 43 mm in the driest. In a month this wet, even a tame spread is a lot of rain in absolute terms — the 96 mm average is a reasonable planning figure, not a promise.

Wind is light at 5.6 km/h, so the temperature on the page is close to the temperature on your skin, and humidity is unremarkable at 73%.

How September sits in the year

The month is on the way down: 5.4 °C cooler than August, with October dropping another 5.1 °C. The first week and the last are not the same trip.

Daylight in September

12.6 hours of daylight, losing 1.7 hours across the month. That is between Graz's extremes of 15.9 and 8.5 hours, so days are long enough not to constrain the plan.

An inland climate

With no coast nearby, the year swings a fair way — 31.3 °C between the warmest afternoons and the coldest nights, wider than any coastal city at this latitude would manage.

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 Graz versus nearby

If Graz is one option among several, the nearby comparison is worth making. Villach is close enough to be a coin toss — within a degree on temperature, 2 days more rain. Zagreb is close enough to be a coin toss — within a degree on temperature, the same number of rain days.

So: September is the answer for Graz. If it is booked out or priced out, May is the next best thing at 5 points behind, and December is the month to keep off the shortlist.

Every month in Graz

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