Your May weather guide
MildWeather in Sydney in May
Sydney in May suits a mild-weather city holiday, not a trip built around heat and swimming. Average highs of 19°C make time outdoors comfortable with a layer handy, while nights around 12°C call for a jacket. The sea averages 20.6°C, so expect a bracing dip rather than an easy warm-water swim. For a UK traveller, the appeal is manageable daytime temperatures; the catch is that this is not a major jump into summer warmth.
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
- 18.9°C
- 9 in 10 days stay below 22°C
- Average night-time low
- 12.2°C
- coldest 10% of nights: 9°C or lower
- Compared with London
- +2.3°C
- London averages 16.6°C in May
- Sea temperature
- 20.6°C
- year to year: 20°C to 22°C
- Sunshine per day (est.)
- 5.8h
- 57% of 10.2 h of daylight
- Rainy days (1 mm+)
- 7
- 46 mm over the month
- Humidity
- 73%
- Days over 25°C
- 1%
- none over 30°C
- Record high 1991-2020
- 26.6°C
- 2018-05-04
- Record low 1991-2020
- 6.0°C
- 2020-05-12
- 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 May compares
May is the 9th warmest month of the year in Sydney and ranks 130th of 134 destinations we compare for May - see where else is hot in May. Against London's average high of 16.6°C in May, Sydney is 2.3°C warmer by day and 3.9°C warmer at night.
Daytime and night-time in May
The typical May day in Sydney peaks at 18.9°C, but that is an average: the warmest 10% of days reach 22.0°C or more. Roughly 1 in 111 days top 25°C. Nights average 12.2°C; one night in ten drops to 9.3°C or lower, so pack a layer for evenings - it is genuinely cool after dark. Between 1991 and 2020 the hottest May day here reached 26.6°C (2018-05-04) and the coldest night 6.0°C (2020-05-12).
Rain in May
Some rain (4-8 rainy days): about 7 days with 1 mm or more, 46 mm in total. Year to year it varies a lot - the wettest May was 1998 with 145 mm, the driest 2008 with 8 mm. Humidity averages 73%.
Sea temperature in May
The sea averages 20.6°C - bracing (18-22°c). Depending on the year it ranges from 19.6°C to 21.6°C. For the warmest sea here, come in February (23.0°C).
Sunshine and daylight
Around 5.8 hours of sunshine a day (estimated from cloud cover), 10.2 hours of daylight: the sun rises about 06:40 and sets about 17:03 local time in mid-May. Average cloud cover is 43%.
Is May a good time to visit Sydney?
May 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.
Comfortable days, but pack for cooler evenings
May is a sensible choice if you prefer walking around without strong heat. Typical afternoons are mild rather than hot, although the warmest 10% of days reach 22°C or more. Days reaching 25°C are unusual, so summer clothing alone would be a poor bet. Pack light layers, trousers and a jacket you can keep with you into the evening. The coldest 10% of nights fall to 9.3°C or below, making an extra warm layer useful if you feel the cold. There is little reason to plan your whole day around avoiding midday heat; instead, use the warmer part of the day for sitting outdoors.
Plan around daylight and leave room for rain
Expect some rain rather than a completely dry holiday: May has about 6 rainy days. A compact umbrella or light waterproof is sensible, and keeping outdoor plans flexible is better than assuming every day will stay clear. Sunshine averages 5.8 hours within 10.2 hours of daylight, so start outdoor plans earlier rather than relying on long, light evenings. Swimming is more of a personal call. At an average of 20.6°C, the sea is bracing, with a year-to-year range of 20°C to 22°C. If you enjoy cooler water, a dip may appeal; if warm swimming is central to the trip, May is a compromise. Have something warm and dry ready afterwards.
A little perspective
Sydney through the year
May 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% |
| MaySelected | 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% |
| August | 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 May
Closest matches on daytime temperature, sea temperature and sunshine, in other countries.
A little more detail
Sydney in May FAQs
Plain answers, grounded in the averages.
Is Sydney hot in May?
Sydney is mild in May: the average daytime high is 18.9°C and nights average 12.2°C. Roughly 1 in 111 May days reach 25°C.
Can you swim in the sea in Sydney in May?
The sea around Sydney averages 20.6°C in May, which is bracing - fine for a quick dip, cool for long swims. Between 1991 and 2020 it ranged from 20°C to 22°C depending on the year.
How much does it rain in Sydney in May?
Sydney sees about 7 rainy days (1 mm or more) and 46 mm of rain in a typical May. The wettest May between 1991 and 2020 was 1998 (145 mm) and the driest was 2008 (8 mm).
How sunny is Sydney in May?
Sydney gets around 5.8 hours of sunshine a day in May out of 10.2 hours of daylight (estimated from average cloud cover).
How does Sydney compare with the UK in May?
Sydney is on average 2.3°C warmer than London by day in May (18.9°C against 16.6°C).
What is the hottest May on record in Sydney?
Between 1991 and 2020 the hottest May day in Sydney reached 26.6°C on 2018-05-04, and the coldest night dropped to 6.0°C on 2020-05-12.
Is Sydney much warmer than London in May?
Not by a large margin during the day. Sydney's average high is 18.9°C, compared with London's 16.6°C, a difference of 2.3°C. That is a modest lift in warmth, rather than a switch from spring conditions to hot summer weather.
Is May worth the long flight from the UK?
May makes sense if you want mild conditions for a city holiday and do not need beach heat. With the flight from London taking about 22 hours, it is harder to justify on warmth alone: daytime temperatures are only modestly above London's.
Which months should I consider instead for warmer weather?
December, January and February are the better months to consider if warmth is your priority. May is a milder alternative for travellers who dislike heat, but it is less suited to a holiday centred on hot days and swimming.
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