Your August weather guide
MildWeather in Sydney in August
Sydney in August suits a city holiday with mild afternoons and cool evenings, rather than a trip built around heat and swimming. Average highs are around 17°C, nights fall to about 9°C, and the sea is cold at 17.5°C. For a UK traveller, that means going somewhere cooler than London in August, not extending the British summer. Go if you prefer exploring in layers; choose another month if warm evenings and comfortable sea swimming are central to your plans.
Long-term climate averages for Sydney, not a forecast · 1991-2020
Sydney, month by month
Your snapshot
At a glance
The useful details for Sydney.
- Average daytime high
- 17.2°C
- 9 in 10 days stay below 21°C
- Average night-time low
- 9.2°C
- coldest 10% of nights: 7°C or lower
- Compared with London
- -4.2°C
- London averages 21.4°C in August
- Sea temperature
- 17.5°C
- year to year: 17°C to 19°C
- Sunshine per day (est.)
- 7.3h
- 68% of 10.7 h of daylight
- Rainy days (1 mm+)
- 5
- 37 mm over the month
- Humidity
- 66%
- Days over 25°C
- 1%
- none over 30°C
- Record high 1991-2020
- 26.8°C
- 1995-08-31
- Record low 1991-2020
- 3.0°C
- 2019-08-15
- Flight from London
- ≈ 22 h
- 17017 km, long-haul (estimate for a direct flight)
Records are observed extremes within 1991-2020, not typical holiday conditions. Warm-day percentages are shares of days, not day counts.
How August compares
August is the 10th warmest month of the year in Sydney and ranks 133rd of 134 destinations we compare for August - see where else is hot in August. Against London's average high of 21.4°C in August, Sydney is 4.2°C cooler by day and 4.3°C cooler at night.
Daytime and night-time in August
The typical August day in Sydney peaks at 17.2°C, but that is an average: the warmest 10% of days reach 20.7°C or more. Roughly 1 in 200 days top 25°C. Nights average 9.2°C; one night in ten drops to 6.6°C or lower, so pack a layer for evenings - it is genuinely cool after dark. Between 1991 and 2020 the hottest August day here reached 26.8°C (1995-08-31) and the coldest night 3.0°C (2019-08-15).
Rain in August
Some rain (4-8 rainy days): about 5 days with 1 mm or more, 37 mm in total. Year to year it varies a lot - the wettest August was 1998 with 181 mm, the driest 1995 with 0 mm. Humidity averages 66%.
Sea temperature in August
The sea averages 17.5°C - too cold for most (under 18°c). Depending on the year it ranges from 16.7°C to 18.6°C. For the warmest sea here, come in February (23.0°C).
Sunshine and daylight
Around 7.3 hours of sunshine a day (estimated from cloud cover), 10.7 hours of daylight: the sun rises about 06:34 and sets about 17:25 local time in mid-August. Average cloud cover is 32%.
Is August a good time to visit Sydney?
August is not the strongest month here: mild days. The best months for Sydney on our scoring are December, January, February; months averaging 25°C or more: Jan, Feb.
Pack for cool evenings, not summer heat
Sydney's average August daytime high is 4.2°C below London's, so your usual summer holiday packing needs adjusting. A light top may suit a milder afternoon, but take a jumper and a jacket for when temperatures drop. The warmer days can reach around 21°C, while the coldest nights fall to around 7°C or lower. That makes layers more useful than packing mainly shorts and sandals. Midday is a sensible time for outdoor plans if you want the most warmth, rather than a period you need to avoid because of heat. August suits travellers who enjoy mild weather and do not mind wrapping up after dark.
Make use of the sunshine, but keep plans flexible
Rain is a consideration rather than the main reason to rule August out: there are about 5 rainy days during the month. Pack a waterproof layer and leave room to move outdoor plans around if a wet spell arrives. About 7.3 hours of sunshine within 10.7 hours of daylight gives you a useful window for being outside, though sunshine does not necessarily mean warmth. Start outdoor days promptly rather than relying on a long, light evening as you might at home in summer. The balance is favourable for a flexible city break, provided you are comfortable with cool conditions and some rain.
A little perspective
Sydney through the year
August is highlighted. See how it compares with the rest of the year.
| Month | Day | Night | Sea | Sun/day | Rain mm | Rainy days | Days 25°C+ |
|---|---|---|---|---|---|---|---|
| Januarybest | 25.7°C | 19.5°C | 22.5°C | 6.3 | 68 | 9 | 53% |
| Februarybest | 25.1°C | 19.5°C | 23.0°C | 5.7 | 87 | 11 | 47% |
| March | 23.8°C | 18.1°C | 22.7°C | 5.9 | 70 | 11 | 29% |
| April | 21.6°C | 15.2°C | 21.9°C | 6.0 | 54 | 8 | 10% |
| May | 18.9°C | 12.2°C | 20.6°C | 5.8 | 46 | 7 | 1% |
| June | 16.5°C | 10.2°C | 19.1°C | 5.4 | 65 | 8 | 0% |
| July | 16.0°C | 8.9°C | 18.0°C | 6.4 | 36 | 6 | 0% |
| AugustSelected | 17.2°C | 9.2°C | 17.5°C | 7.3 | 37 | 5 | 1% |
| September | 19.6°C | 11.4°C | 17.7°C | 7.4 | 40 | 6 | 7% |
| October | 21.5°C | 13.7°C | 18.6°C | 6.7 | 51 | 8 | 18% |
| November | 22.7°C | 15.7°C | 19.6°C | 6.0 | 70 | 9 | 24% |
| Decemberbest | 24.4°C | 17.7°C | 21.0°C | 6.3 | 56 | 9 | 39% |
Day = average daytime high, night = average night-time low, 1991-2020.Sun is hours per day; rainy days count 1 mm or more.
Day, night and sea
Monthly average temperatures, 1991-2020
- Day
- Night
- Sea
Best months here
On warmth, low rainfall and sunshine, start with these.
Keep exploring
Similar in August
Closest matches on daytime temperature, sea temperature and sunshine, in other countries.
A little more detail
Sydney in August FAQs
Plain answers, grounded in the averages.
Is Sydney hot in August?
Sydney is mild in August: the average daytime high is 17.2°C and nights average 9.2°C. Roughly 1 in 200 August days reach 25°C.
Can you swim in the sea in Sydney in August?
The sea around Sydney averages 17.5°C in August, which is cold for swimming without a wetsuit. Between 1991 and 2020 it ranged from 17°C to 19°C depending on the year.
How much does it rain in Sydney in August?
Sydney sees about 5 rainy days (1 mm or more) and 37 mm of rain in a typical August. The wettest August between 1991 and 2020 was 1998 (181 mm) and the driest was 1995 (0 mm).
How sunny is Sydney in August?
Sydney gets around 7.3 hours of sunshine a day in August out of 10.7 hours of daylight (estimated from average cloud cover).
How does Sydney compare with the UK in August?
Sydney is on average 4.2°C cooler than London by day in August (17.2°C against 21.4°C).
What is the hottest August on record in Sydney?
Between 1991 and 2020 the hottest August day in Sydney reached 26.8°C on 1995-08-31, and the coldest night dropped to 3.0°C on 2019-08-15.
Is the sea warm enough for swimming in August?
At an average of 17.5°C, the sea is cold rather than comfortably warm. Even the year-to-year range of 17°C to 19°C stays below the 22°C swimming benchmark. August is a poor fit if relaxed sea swimming is the main aim.
Is August worth the long flight from London?
The flight from London takes about 22 hours, so August makes more sense if Sydney itself is the draw than if you mainly want warmth. Expect mild daytime weather, cool nights and a colder sea, rather than a hot-weather reward for the journey.
Which months are better for a summer-weather trip?
December, January and February are the strongest choices overall for Sydney holiday weather. August is among the city's cooler months, so choose it for mild conditions rather than summer heat. Those summer months are a better starting point if warmth matters most.
About these averages
ERA5-Land climate reanalysis via Open-Meteo (11 km grid) and NOAA Coral Reef Watch 5 km sea temperatures, 1991-2020
Averages computed from daily values at Sydney. Sea temperature from the nearest 5 km sea cell, 1.8 km from that point. Sunshine hours are estimated from average cloud cover.Records are the highest and lowest daily values in that 30-year period, not all-time records. These are climate averages, not a forecast for your trip. How we measure holiday weather
- Hot · 25°C+
- Warm · 20°C to below 25°C
- Mild · 15°C to below 20°C
- Cool · below 15°C