Weather in Bunbury in September

A good month. September is a solid month to be in Bunbury. Highs average 17.6 °C, lows 9.8 °C, and rain falls on 14 days — nothing in the month is working against you.

September ranks 9 of 12 in Bunbury: past the worst of the year but short of November, which is the month to book if the dates are open.

Rain on 14 days, 3 of them heavy. Enough to need a plan B, not enough to need a plan around it. Pack for 17.6 °C days and 9.8 °C nights; the spread matters more here than any single number.

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 25.5 °C and the coldest night fell to 3.6 °C, and the wettest single day dropped 35 mm — roughly 39% of the month's rain in one day.

September is moderately variable: 27 mm in the driest year against 194 mm in the wettest, around an average of 89 mm. Roughly two Septembers in three land near that average, and the third does something else entirely.

Wind is light at 12.9 km/h, so the temperature on the page is close to the temperature on your skin, and humidity runs at 79%, high enough to notice on the warm days without dominating them.

How September sits in the year

Temperatures hold steady either side: 16.7 °C in August, 17.6 here, 20.5 in October. Nothing about the timing within the month matters much. Rain is the thing that moves: October brings 6 days less of it, so pushing the dates later buys drier weather.

Daylight in September

11.8 hours of daylight, gaining 1 hours across the month. That is between Bunbury's extremes of 14.3 and 10 hours, so days are long enough not to constrain the plan.

Sea temperature

The sea sits at about 18.7 °C in September — swimmable, but it takes a moment to commit. The sea peaks at 22.7 °C in March and bottoms out at 18.7 °C — water lags the air by a month or two, which is why the best swimming often comes after the best weather.

How busy it gets

Quiet. Few other visitors, cheaper rooms, and a real chance some seasonal operators are shut.

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

September in Bunbury versus nearby

If Bunbury is one option among several, the nearby comparison is worth making. Perth is close enough to be a coin toss — within a degree on temperature, 3 days less rain. Albany is close enough to be a coin toss — within a degree on temperature, the same number of rain days.

So: September is a compromise. November is 23 points better and is what Bunbury is actually like at its best — worth moving the trip for if that is possible, and worth adjusting expectations for if it is not.

Every month in Bunbury

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