How warm is it in Sydney in May?

Daytime highs averaged 19.8 °C, night-time lows 15.3 °C. The highest value of the past 10 years was 25.3 °C (21 May 2019), the lowest 9.9 °C (30 May 2017).

How often does it rain in Sydney in May?

On average there were 8.6 rain days (at least 1 mm) with 48.2 mm of precipitation in total.

How warm is the sea in Sydney in May?

The sea temperature averaged 21.0 °C (open-sea point approx. 10 km from the town).

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Sydney weather in May: temperature & rain

Photo: Diliff · CC BY-SA 3.0

🇦🇺 Weather in Sydney in May

This is what the weather in Sydney (New South Wales, Australia) was like in May over the years 2017–2026.

Key facts at a glance

Prevailing weather: Partly cloudy

Avg. daytime high

19.8 °C

18.7 °C – 21.2 °C

Avg. night-time low

15.3 °C

13.9 °C – 17.2 °C

Avg. rain days in period

8.6

28 % of days · ≥ 1.0 mm

Avg. precipitation in period

48.2 mm

7.4 mm – 126 mm

Avg. cloud cover

58 %

This data source has no sunshine hours – average cloud cover is shown instead.

Avg. sea temperature

21.0 °C

Sea measuring point approx. 10 km from the location

Extremes: Highest temperature 25.3 °C (21 May 2019) · Lowest temperature 9.9 °C (30 May 2017) · Avg. daily peak wind 19 km/h

Weather mix of all days

54Sunny
122Partly cloudy
48Cloudy
59Light rain
27Rain

Summary

On average 19.8 °C during the day and 15.3 °C at night.
On average 8.6 rain days (Rain day = at least 1.0 mm of precipitation) with 48.2 mm of precipitation in total.
The sea averaged 21.0 °C.
Prevailing weather: Partly cloudy.
Warmest year: 2019 (avg. 21.2 °C), coolest: 2020 (avg. 18.7 °C).
Wettest year: 2025 (126 mm), driest: 2018 (7.4 mm).
Extremes: 25.3 °C on 21 May 2019 and 9.9 °C on 30 May 2017.

Overall values from all 10 years. How is this calculated?

Temperatures per year

Average over your travel period

Precipitation & rain days

Year by year

2026
Avg. max20.7°Avg. min17.2°
Rain days
14 Rain days
Precipitation
78.2 mm
Avg. cloud cover
65 % cloudy
Sea temperature
21.5 °C
Max 23.9 °C · Min 12.4 °C
2025
Avg. max20.2°Avg. min16.5°
Rain days
15 Rain days
Precipitation
126 mm
Avg. cloud cover
72 % cloudy
Sea temperature
21.0 °C
Max 24.8 °C · Min 11.7 °C
2024
Avg. max19.5°Avg. min16.0°
Rain days
13 Rain days
Precipitation
76.2 mm
Avg. cloud cover
62 % cloudy
Sea temperature
20.9 °C
Max 21.2 °C · Min 12.8 °C
2023
Avg. max19.2°Avg. min13.9°
Rain days
6 Rain days
Precipitation
17.9 mm
Avg. cloud cover
41 % cloudy
Sea temperature
21.0 °C
Max 22.6 °C · Min 9.9 °C
2022
Avg. max19.4°Avg. min15.9°
Rain days
14 Rain days
Precipitation
65.0 mm
Avg. cloud cover
56 % cloudy
Sea temperature
22.8 °C
Max 23.2 °C · Min 11.5 °C
2021
Avg. max18.9°Avg. min14.6°
Rain days
8 Rain days
Precipitation
45.0 mm
Avg. cloud cover
60 % cloudy
Sea temperature
19.9 °C
Max 22.3 °C · Min 10.8 °C
2020
Avg. max18.7°Avg. min14.6°
Rain days
8 Rain days
Precipitation
44.4 mm
Avg. cloud cover
63 % cloudy
Sea temperature
20.3 °C
Max 23.1 °C · Min 12.0 °C
2019
Avg. max21.2°Avg. min15.3°
Rain days
3 Rain days
Precipitation
10.4 mm
Avg. cloud cover
52 % cloudy
Sea temperature
22.2 °C
Max 25.3 °C · Min 10.6 °C
2018
Avg. max20.3°Avg. min14.3°
Rain days
2 Rain days
Precipitation
7.4 mm
Avg. cloud cover
53 % cloudy
Sea temperature
19.4 °C
Max 25.0 °C · Min 11.3 °C
2017
Avg. max19.8°Avg. min15.1°
Rain days
3 Rain days
Precipitation
12.0 mm
Avg. cloud cover
60 % cloudy
Sea temperature
21.2 °C
Max 22.6 °C · Min 9.9 °C

Frequently asked questions

How warm is it in Sydney in May?: Daytime highs averaged 19.8 °C, night-time lows 15.3 °C. The highest value of the past 10 years was 25.3 °C (21 May 2019), the lowest 9.9 °C (30 May 2017).
How often does it rain in Sydney in May?: On average there were 8.6 rain days (at least 1 mm) with 48.2 mm of precipitation in total.
How warm is the sea in Sydney in May?: The sea temperature averaged 21.0 °C (open-sea point approx. 10 km from the town).

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Data sources

Weather data: Data obtained from the NASA Langley Research Center (LaRC) POWER Project funded through the NASA Earth Science/Applied Science Program
Reanalysis (weather model constrained by observations) on a coarse grid of about 50 km. Values represent a large area and can differ from local conditions, especially on islands, coasts and in mountains. Snow depth is the model value for the grid cell, not the depth on the slopes. No sunshine duration.
Reanalysis (weather model constrained by observations)
Reanalysis values represent a grid cell (approx. 25–50 km) and may differ from local measurements on coasts, islands and in mountains.
Sea temperature: MUR SST data were provided by JPL under support by NASA MEaSUREs program; accessed via NOAA CoastWatch ERDDAP
Daily multi-scale ultra-high resolution (≈ 1 km) analysis of satellite measurements (infrared, microwave) and in-situ data. Represents the foundation temperature below the daily warm surface layer. (Satellite and in-situ analysis); Sea measuring point approx. 10 km from the location (-33.870, 151.320)
Place search: Natural Earth (public domain) · GeoNames (CC BY 4.0) / OpenStreetMap (ODbL)