Weather in Byron Bay in December

A good month. December is a solid month to be in Byron Bay. Highs average 25.5 °C, lows 23 °C, and rain falls on 14 days — nothing in the month is working against you.

December ranks 10 of 12 — near the bottom of Byron Bay's year. August is the month that works, and the swing between the two is 23 points, which is a different holiday rather than a slightly better one. Worth keeping in perspective: December is the weakest month of Byron Bay's year and it is still a perfectly good one. The downside here is small.

Rain on 14 days, 4 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 December reaches 30 °C; the day barely swings — 2.5 °C between the overnight low and the afternoon high. Across the twenty years measured, the hottest December day reached 31.1 °C and the coldest night fell to 18.6 °C, and the wettest single day dropped 131 mm — roughly 98% of the month's rain in one day.

December is moderately variable: 31 mm in the driest year against 380 mm in the wettest, around an average of 134 mm. Roughly two Decembers in three land near that average, and the third does something else entirely.

Wind sits around 20.6 km/h — a steady breeze rather than a nuisance, and welcome on the warmer days, and humidity runs at 76%, high enough to notice on the warm days without dominating them.

How December sits in the year

Temperatures hold steady either side: 24.1 °C in November, 25.5 here, 26.3 in January. Nothing about the timing within the month matters much.

Daylight in December

December is at or near the longest days of Byron Bay's year: 13.9 hours of daylight, holding steady all month. Evenings are the real gain — dinner outdoors still happens in full light.

Sea temperature

The sea sits at about 25.3 °C in December — warm enough to stay in as long as you like. The sea peaks at 26.5 °C in February and bottoms out at 21.5 °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

Shoulder. The value months — prices ease off and you get the place closer to itself.

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

December in Byron Bay versus nearby

If Byron Bay is one option among several, the nearby comparison is worth making. Brisbane is the weaker option in December — 3.1 °C warmer, the same number of rain days. Coffs Harbour is close enough to be a coin toss — within a degree on temperature, 1 day more rain.

So: December works, with August the better month by 16 points if the dates can move. If they cannot, nothing here should stop you booking.

Every month in Byron Bay

See all twelve months in Byron Bay, or where else to go in December.