Weather in Coffs Harbour in September

Prime time. If you get to pick your dates, September is the one. Highs average 21.7 °C, lows 15.9 °C, and rain falls on 7 days — nothing in the month is working against you.

September ranks 2 of 12 in Coffs Harbour. Only August scores clearly higher, and the difference is small enough to be settled by price rather than weather.

Rain on 7 days, 1 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; the day barely swings — 5.8 °C between the overnight low and the afternoon high. Across the twenty years measured, the hottest September day reached 30.9 °C and the coldest night fell to 10.9 °C, and the wettest single day dropped 63 mm — roughly 143% of the month's rain in one day.

September is moderately variable: 3 mm in the driest year against 114 mm in the wettest, around an average of 44 mm. Roughly two Septembers in three land near that average, and the third does something else entirely.

Wind is light at 12 km/h, so the temperature on the page is close to the temperature on your skin, and humidity is unremarkable at 70%.

How September sits in the year

The month is on the way up: 2.3 °C warmer than August, and October adds another 1.8 °C. Late in the month feels noticeably different from the start of it, which is worth knowing if the trip is short. Rain is the thing that moves: October brings 5 days more of it, so the earlier half of a flexible trip is the safer half.

Daylight in September

11.9 hours of daylight, gaining 0.9 hours across the month. That is between Coffs Harbour's extremes of 14.1 and 10.2 hours, so days are long enough not to constrain the plan.

Sea temperature

The sea sits at about 20.7 °C in September — swimmable, but it takes a moment to commit. The sea peaks at 25.8 °C in February and bottoms out at 20.5 °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

Peak season. Expect the highest prices of the year and to be booking well ahead. If the dates are flexible, October is the trade worth considering — 10 points weaker on weather, and materially quieter.

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

September in Coffs Harbour versus nearby

If Coffs Harbour is one option among several, the nearby comparison is worth making. Armidale is close enough to be a coin toss — 3.5 °C cooler, the same number of rain days. Byron Bay is close enough to be a coin toss — within a degree on temperature, the same number of rain days.

So: September is effectively as good as it gets here — 0 points behind August, which is inside the margin where the weather stops being the deciding factor and price starts being it.

Every month in Coffs Harbour

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