Weather in Kalgoorlie in December

A hard month. December is a hard month in Kalgoorlie, and worth planning around. Daytime highs average 34.4 °C and the afternoon is not negotiable — outdoor plans move to early morning or evening.

December ranks 12 of 12 — near the bottom of Kalgoorlie's year. May is the month that works, and the swing between the two is 47 points, which is a different holiday rather than a slightly better one.

Rain falls on only 4 days, so an itinerary with no wet-weather fallback is a reasonable risk. 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: 14 days clear 35 °C, so a serious heatwave is normal rather than notable; the day swings 18 °C from low to high, which means one bag has to cover both. Across the twenty years measured, the hottest December day reached 45.8 °C and the coldest night fell to 9.2 °C, and the wettest single day dropped 25 mm — roughly 114% of the month's rain in one day.

December is moderately variable: 1 mm in the driest year against 51 mm in the wettest, around an average of 22 mm. Roughly two Decembers in three land near that average, and the third does something else entirely.

Wind is light at 14.3 km/h, so the temperature on the page is close to the temperature on your skin, and the air is dry at 36% humidity, which makes the heat far more bearable than the same figure somewhere humid — and dehydrates you faster than you expect.

How December sits in the year

The month is on the way up: 2.8 °C warmer than November, and January adds another 2 °C. Late in the month feels noticeably different from the start of it, which is worth knowing if the trip is short.

Daylight in December

December is at or near the longest days of Kalgoorlie's year: 14.1 hours of daylight, holding steady all month. Evenings are the real gain — dinner outdoors still happens in full light.

An inland climate

With no coast nearby, the year swings a fair way — 31.4 °C between the warmest afternoons and the coldest nights, wider than any coastal city at this latitude would manage. Within December itself the daily swing is 18 °C, so mornings and afternoons need different clothes.

How busy it gets

Off season. The genuine off season: cheapest by a distance, with the caveat that some tours and restaurants close entirely.

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

December in Kalgoorlie versus nearby

If Kalgoorlie is one option among several, the nearby comparison is worth making. Perth is a better bet in December — 9.8 °C cooler, 1 day less rain. Albany is a better bet in December — 13.6 °C cooler, 2 days more rain.

So: December is a compromise. May is 47 points better and is what Kalgoorlie 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 Kalgoorlie

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