Adelaide and Sydney have similar daytime temperatures, Sydney has 5.4°C (9.7°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 12 of 12 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 January, March and December in Adelaide and March, April and December in Sydney.
| Adelaide | Metric | Sydney |
|---|---|---|
| 🌡️ Temperature | ||
| 21.5°C | 🌡️Average daytime high | 21.1°C |
| 10.7°C | 🌙Average nighttime low | 16.1°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 10.7°C (51.3°F) while Sydney settles near 16.1°C (61°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 March, April and December.
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 | 15.4 | 22.3🔥 | 29.3 | 20.2 | 22.8🔥 | 25.4 |
| February | 15.5 | 22.3 | 29.2 | 20.5 | 22.8 | 25.1 |
| March | 14.1 | 20.2 | 26.4 | 19.6 | 21.8 | 24 |
| April | 11.6 | 16.9 | 22.2 | 17.5 | 19.7 | 21.9 |
| May | 9.4 | 13.7 | 18 | 15 | 17.2 | 19.3 |
| June | 7.2 | 11 | 14.8 | 12.6 | 14.7 | 16.8 |
| July | 6.3 | 10❄️ | 13.8 | 11.4 | 13.8❄️ | 16.1 |
| August | 6.5 | 10.7 | 14.9 | 11.7 | 14.4 | 17.1 |
| September | 7.8 | 12.7 | 17.6 | 13.4 | 16.3 | 19.3 |
| October | 9.4 | 15.1 | 20.9 | 15.2 | 18.2 | 21.2 |
| November | 11.7 | 18 | 24.3 | 16.9 | 19.7 | 22.5 |
| December | 13.6 | 20.2 | 26.9 | 18.7 | 21.5 | 24.3 |
| Annual Avg | 10.7 | 16.1 | 21.5 | 16.1 | 18.6 | 21.1 |
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 and Sydney are about equally warm. Daytime highs average 21.5°C (70.7°F) in Adelaide and 21.1°C (70°F) in Sydney, so neither is clearly the warmer choice over the year. Nights are milder in Sydney, with average lows of 16.1°C (61°F) versus 10.7°C (51.3°F).
Adelaide is hottest in January, averaging highs of about 29.3°C (84.8°F), while Sydney peaks in January at around 25.4°C (77.7°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 6.3°C (43.3°F), compared with 11.4°C (52.6°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 January, March and December, when average temperatures are at their mildest.
Sydney is at its most pleasant around March, April and December, based on the mildest average temperatures of the year.
Sydney is the warmer city in all 12 months of the year. The gap is widest in July, about 3.8°C (6.8°F), and narrowest in January, about 0.5°C (0.9°F).
Adelaide has the bigger seasonal swing, about 12.3°C (22.1°F) between its coldest and hottest months versus 9°C (16.2°F) in Sydney — so Sydney has the steadier, more even climate.
On climate alone, Adelaide comes out ahead — it offers less rain and lower humidity than Sydney. Sydney is the better fit only if you'd actually prefer 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.
