Adelaide is 3.1°C (5.6°F) warmer by day, Sydney has 6.6°C (11.9°F) warmer nights, Sydney gets 510 mm (20.1 in) more rain a year.
Adelaide is at its warmest in January and coolest in July, while Sydney peaks in January and bottoms out in July. Month for month, Sydney is the warmer of the two in 10 of 11 months.
Sydney is the wetter of the two, collecting 963 mm (37.9 in) of rain a year against 453 mm (17.8 in) in Adelaide. The most comfortable time to visit is March, April and November in Adelaide and April, October and November in Sydney.
| Adelaide | Metric | Sydney |
|---|---|---|
| 🌡️ Temperature | ||
| 29.6°C | 🌡️Average daytime high | 26.5°C |
| 6.4°C | 🌙Average nighttime low | 13°C |
| January | 🔥Hottest month | January |
| July | ❄️Coldest month | July |
| 🌧️ Rain | ||
| 453 mm | 🌧️Annual rainfall | 963 mm |
| July | ☔Wettest month | February |
| February | 🏜️Driest month | September |
| 💨 Climate | ||
| 65% | 💧Average humidity | 73% |
| 2.8 m/s | 💨Average wind speed | 3.2 m/s |
Overnight, Adelaide typically falls to around 6.4°C (43.5°F) while Sydney settles near 13°C (55.4°F).
Adelaide is hottest in January and coldest in July, whereas Sydney peaks in January and is coolest in July.
Adelaide sees the most rain in July and the least in February; Sydney is wettest in February and driest in September.
Sydney feels the more humid of the two, averaging 73% relative humidity against 65%.
For Sydney, the pick of the year is April, October and November.
Month by month, here is the coldest night, the average day and the hottest afternoon each city can expect. Switch Compare to read rainfall, humidity, wind or solar instead, and Period to move between the long-term 45-year average and any single year — the shading is a quick warm-to-cool guide.
| Month | Adelaide | Sydney | ||||
|---|---|---|---|---|---|---|
| Min | Avg | Max | Min | Avg | Max | |
| January | 11 | 25.6🔥 | 40.1 | 17.8 | 25.4🔥 | 32.9 |
| February | 11 | 24.8 | 38.6 | 18 | 24.8 | 31.6 |
| March | 9.4 | 22.5 | 35.6 | 16.6 | 22.9 | 29.3 |
| April | 7.2 | 18.7 | 30.2 | 14 | 20.1 | 26.2 |
| May | 4.7 | 14.4 | 24.1 | 11.4 | 17.2 | 23 |
| June | 2.8 | 11.1 | 19.3 | 9 | 14.4 | 19.8 |
| July | 2.1 | 10.1❄️ | 18.1 | 8.4 | 14❄️ | 19.6 |
| August | 2.7 | 11.9 | 21 | 8.8 | 15 | 21.2 |
| September | 3.8 | 14.8 | 25.7 | 10.3 | 17.6 | 24.9 |
| October | 5.2 | 17.8 | 30.4 | 12.1 | 20.1 | 28.1 |
| November | 7.1 | 21 | 34.9 | 13.5 | 21.6 | 29.8 |
| December | 9.2 | 23.4 | 37.6 | 15.7 | 23.7 | 31.8 |
| Annual Avg | 6.4 | 18 | 29.6 | 13 | 19.7 | 26.5 |
Min / mean / max temperature (°C). 🔥 marks each city's hottest month, ❄️ its coldest; shading runs cool blue to warm red.
The same figures plotted out, so the shape of a typical year is easier to see than in a grid. Where the two lines run close together Adelaide and Sydney feel alike; where they separate, they are genuinely different places to be.
Hover or tap any point to read the exact figures. Adelaide Sydney
See how Adelaide and Sydney stack up against other cities. Swipe for more.
Choose which city to keep, then search for any other city in our database — we'll build the comparison for you.
Quick answers to the questions people ask most when comparing Adelaide and Sydney — each drawn straight from the climate figures above.
Adelaide is the warmer of the two. It averages daytime highs of 29.6°C (85.3°F) against 26.5°C (79.7°F) in Sydney — roughly 3.1°C (5.6°F) warmer by day. Nights are milder in Sydney, with average lows of 13°C (55.4°F) versus 6.4°C (43.5°F).
Adelaide is hottest in January, averaging highs of about 40.1°C (104.2°F), while Sydney peaks in January at around 32.9°C (91.2°F). That makes Adelaide the hotter of the two at the height of summer.
Adelaide gets colder. In its coldest month (July) overnight lows average about 2.1°C (35.8°F), compared with 8.4°C (47.1°F) at the low point of the year in Sydney.
Sydney is the wetter city, collecting about 963 mm (37.9 in) of rain a year versus 453 mm (17.8 in) in Adelaide. Adelaide is wettest in July and driest in February; Sydney is wettest in February and driest in September.
Sydney is the more humid of the two, averaging 73% relative humidity over the year against 65% in Adelaide.
The most comfortable months in Adelaide are March, April and November, when average temperatures are at their mildest.
Sydney is at its most pleasant around April, October and November, based on the mildest average temperatures of the year.
Sydney is the warmer city in 10 of the 11 months of the year. The gap is widest in July, about 3.9°C (7°F), and narrowest in February, about 0°C (0°F).
Adelaide has the bigger seasonal swing, about 15.5°C (27.9°F) between its coldest and hottest months versus 11.4°C (20.5°F) in Sydney — so Sydney has the steadier, more even climate.
On climate alone, Adelaide comes out ahead — it offers warmer days, less rain and lower humidity than Sydney. Sydney is the better fit only if you'd actually prefer cooler weather, more rainfall and a more humid climate.
Every figure on this page is calculated from NASA POWER satellite climate data spanning 1981–2025 (45 years). The averages describe the long-term climate of Adelaide and Sydney, not a single year's weather or a short-range forecast.
