Adelaide weather in December

December in Adelaide: warm, dry, with clean air — an excellent time to visit.

Updated September 2026 · climate normals from ERA5 reanalysis

Adelaide🇦🇺 Australia · Southeast Australia & Tasmania · City91
  1. 85Jan
  2. 89Feb
  3. 92Mar
  4. 93Apr
  5. 82May
  6. 74Jun
  7. 76Jul
  8. 79Aug
  9. 87Sep
  10. 93Oct
  11. 94Nov
  12. 91Dec

#5 of 12 months in Adelaide · #50 of 1413 destinations to visit in December · comfort 91/100 (tier S)

Days
28°C
Nights
15°C
Wet days
3
Sun
12.3 h
Humidity
56%
Daylight
15 h
Adelaide, Australia
Photo: Ryan Vand · Pexels

Traveller notes on Adelaide in December

Regulars describe genuinely wide year-to-year swings around the holidays here - some Christmas Days landing in full heatwave conditions near 40C, others turning cool with rain and wind instead - with no way to know in advance which version a given trip will get. Our row backs the warm, still-comfortable average sitting well below either extreme, 27.7C over 15.3C nights feeling 13C, with rain light at 20.4mm across just 3.1 days. Regulars traveling with elderly relatives or young kids specifically recommend building in air-conditioned downtime, the Adelaide Hills a popular escape when a heatwave does hit, and keeping the day's plans flexible enough to swap outdoor time for indoor if needed. The sea sits at a swimmable 20.3C. The record: humidity 56 percent, 12.3 hours of sun, a 24.8 kph wind and one of the cleanest air readings in this project, AQI 26.
SomeChristmasesHeatwaveOthersRainAndWind · December · 1 month ago · Read more on Tripadvisor ↗

Other months in Adelaide

October here is lovely and unreliable in the same breath - regulars tell visitors to bring jumpers and light coats as well as summer clothes, because winter can hang on into the month. Our row gives 22.5C reading as 21C over 11.8C nights that feel like 8C, and the reason is the wind: 24.8 kph, because spring here is windier than autumn. Rain has eased to 35.8mm across 6.4 days. The vineyards an hour out - the Barossa to the east, McLaren Vale to the south - are green and leafy after the winter rain and quiet in their own calendar. The sea is 17.2C, which is looking rather than swimming. The record: humidity 65 percent, 10.7 hours of sun and AQI 27.
PackForTwoSeasons · October · 1 month ago · Read more on Tripadvisor ↗
April here is defined by what has just ended. March is the festival month - Fringe, the Adelaide Festival, WOMADelaide and a motor race, all at once - and April is the city afterwards: the summer heat gone, the cold not arrived, cool nights under crisp clear skies. Regulars warn the changeover is untidy, with summer sometimes running into April and occasional cool days early, and they put the month at mid-twenties by day and 12 to 14C at night against February's forties. Our row reads 23.4C over 13.1C with only 27.1mm across 4.4 days. The record: humidity 64 percent, 9.2 hours of sun, a 18.9C sea and AQI 22, the cleanest air in this collection.
TheMonthAfterMadMarch · April · 1 month ago · Read more on Tripadvisor ↗
November in Adelaide is warm without being hot - regulars give a mean maximum near 25C and a minimum near 14C, which our row matches at 24.7C and 13.5C - under mostly sunny skies, with about four rainy days in the month and not much in them. The Mediterranean climate is the reason they give for it rarely feeling humid or muggy; they quote roughly 40 percent humidity, where our row's 61.5 percent is a whole-day mean that includes the nights, so read theirs as the afternoon figure. The local name for the month is blow-vember, because the afternoon sea breeze comes in hard, and our row's 24.8 kph is that breeze. Occasional heatwaves aside, this is the comfortable end of an Australian spring. The record: 6.2 precipitation days carrying 40.6mm, 11.7 hours of sun and a 19C sea.
Blowvember · November · 1 month ago · Read more on Tripadvisor ↗
Adelaide forum threads describe January as hot and genuinely unpredictable, with typical daytime highs cited around 30-35C but posters noting it's not uncommon for temperatures to push past 40C on the hottest days, or conversely drop to a much cooler day in the same stretch. Evenings were described as usually 20-25C but occasionally staying in the 30s during a real heatwave. Posters were consistent that there's little way to predict a specific day's weather with confidence - it could be 23C or 43C in the middle of January. The standard advice was light, breathable clothing like cotton, a long-sleeve layer for sun protection, and planning outdoor activities around the heat, with beach access or a pool cited as a real asset for any January stay.
GlenelgBeachRegular · January · 1 month ago · Read more on Tripadvisor ↗

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Adelaide climate normals — December

Daytime high28°C / 82°F🌤 warm
Nighttime low15°C / 60°F
Feels like (high)27°C / 81°F
Sea temperature20°C / 69°F🌊 fresh
Rainfall20 mm / 0.8 in☀️ dry
Rainy days3 days
Humidity56%🍃 comfortable
Dew point10°C / 49°F
Sunshine12.3 h/day
Daylight14.5 h
Wind25 km/h / 15 mph
Air quality (US AQI)26🍃 good

Monthly averages from ERA5 reanalysis. AQI is the mean US Air Quality Index for the month.

Crowds in Adelaide in December

How busy the place itself is — school and mass holidays, the months an editor tagged, and how sought-after the weather makes them. Never part of the comfort score.

Peak crowdsChristmas and Boxing Day, Summer holidays in Australia, school holidays in 3 of the markets that fill it(estimated)

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Peak crowdsBusyShoulder seasonQuiet

Best months for Adelaide's weather

Ranked by this destination's own climate comfort score across the year — a different thing from how busy it gets (see Crowds above).

Fair weatherAdelaide's best weather comes in April, October and November — separate windows, not one continuous season.

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Best weatherFair weatherToughest weather

What's on in Adelaide in December

Recurring seasonal events, natural spectacles, closures and holidays — curated and sourced.

  • Hazard

    Heat and fire danger season

    15 Nov – 15 Mar · usuallyExtreme heat

    A run of hot northerlies can put the Hills and the Fleurieu on catastrophic fire danger and bring a total fire ban; the country fire service rates each district a day at a time. Source ↗

  • Holiday

    Christmas and Boxing Day

    24 Dec – 1 JanChristmas & New YearClosuresCrowded

    Christmas Day, Boxing Day and New Year's Day are public holidays at the start of the long summer break: many shops, cafes and tours close on Christmas Day, Boxing Day sales fill the shopping centres, and much of the country is away on holiday until late January. Source ↗

What's on around the world in December →

Nearby, and something's on

Within 300 km of Adelaide — a day trip or a short hop — with something on this month. Never part of the comfort score.

Where is Adelaide?

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Adelaide in December — FAQ

Is December a good time to visit Adelaide?
December in Adelaide: warm, dry, with clean air — an excellent time to visit. It ranks #5 of 12 months for Adelaide on SeasonMap's comfort score (91/100).
What is the weather like in Adelaide in December?
In December, Adelaide averages a daily high of 27.7°C and a low of 15.3°C, with about 20.4 mm of rain over roughly 3.1 rainy days.
What is the air quality in Adelaide in December?
Adelaide has a mean US Air Quality Index of about 26 in December.

Within 300 km: Kangaroo Island's Seal Bay, ranger access only on 1 Jan – 31 Dec.