Weather in Broome in September

A hard month. September is a hard month in Broome, and worth planning around. Daytime highs average 36.1 °C and the afternoon is not negotiable — outdoor plans move to early morning or evening.

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

Rain is not a factor worth planning around this month. Pack for heat management rather than style: shade, water, and a schedule that gives up on the middle of the day.

What the averages hide

Averages flatten a month, and this one hides a few things: 21 days of the month clear 35 °C — that is not a heatwave, it is the month; the day swings 15.6 °C from low to high, which means one bag has to cover both. Across the twenty years measured, the hottest September day reached 41.6 °C and the coldest night fell to 12.7 °C.

September is dependably dry, and that reliability is the point: across the twenty years measured, the wettest September on record still only managed 10 mm, and the driest managed 0 mm. There is no meaningful variability to plan around, which makes this one of the few months anywhere that you can build a fixed outdoor itinerary against without a fallback. The wettest single day in twenty years of Septembers brought 7 mm. Rain simply is not the variable that decides this trip — heat, crowds and cost are.

Wind is light at 11.1 km/h, so the temperature on the page is close to the temperature on your skin, and humidity is unremarkable at 46%.

How September sits in the year

The month is on the way up: 3.6 °C warmer than August, and October adds another 2.7 °C. Late in the month feels noticeably different from the start of it, which is worth knowing if the trip is short.

Daylight in September

12 hours of daylight, gaining 0.5 hours across the month. That is between Broome's extremes of 13.2 and 11.1 hours, so days are long enough not to constrain the plan.

Sea temperature

The sea sits at about 25.3 °C in September — warm enough to stay in as long as you like. The sea peaks at 30.2 °C in March and bottoms out at 24.7 °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 Broome versus nearby

If Broome is one option among several, the nearby comparison is worth making. Labuan Bajo is a better bet in September — 4.2 °C cooler, 8 days more rain. Darwin is a better bet in September — 3.7 °C cooler, 4 days more rain.

So: September is a compromise. June is 35 points better and is what Broome 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 Broome

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