Rottnest Island Temperature by Month
The average annual maximum temperature in Rottnest Island, Western Australia, Australia is 22°C (72°F), with daytime highs ranging from 19°C (66°F) in August to 26°C (79°F) in February. This page covers monthly averages, day-night differences, and how Rottnest Island compares to cities worldwide.
Rottnest Island Monthly Temperatures
The moderate changes in the climate in Rottnest Island ensure gradual weather shifts through each season. At night, temperatures drop to between 21°C (70°F) and 14°C (57°F) depending on the time of year.
The chart below illustrates the average maximum day and minimum night temperatures in Rottnest Island by month:
The minimum temperature is often recorded between 4 AM and 6 AM, while the highest temperature is usually reached at 3 PM, when the sun's heating effect is strongest. February, the warmest month, gets 320 hours of sunshine.
The chart below shows the average temperature throughout the year:
Temperature: Rottnest Island vs Australia
The map below shows the annual temperature across Australia. You can also select individual months if you want to compare a specific time of year.
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Rottnest Island vs World: Temperature Compared
Rottnest Island's average annual maximum temperature is 22°C (72°F). To put that in context, here's how it compares to a few well-known destinations:
Lisbon, Portugal averages 21°C (70°F) annually — warm summers, mild winters, and rain mainly in the cooler months.
Reykjavík, Iceland averages 9°C (48°F) a year — mild summers by Icelandic standards, but cold winters and frequent wind.
New York City, USA averages 17°C (63°F) a year, with hot humid summers and cold winters that bring regular snowfall.
Adelaide, Australia averages 21°C (70°F) a year, with warm summers, mild winters, and relatively low rainfall year-round.
What Does the Temperature Feel Like in Rottnest Island?
Temperature alone doesn't tell the whole story — humidity plays a big role in how warm or cold it actually feels. High humidity in summer makes the heat feel more intense, particularly once temperatures climb above 25°C. In winter, the same humidity can make cold air feel sharper than the thermometer suggests.
In Rottnest Island, August is the coolest month, with average highs of 19°C (66°F) and humidity around 54% — considered moderate. In February, the warmest month, temperatures average 26°C (79°F) with 38% humidity — conditions that feel low. For a full picture, see our humidity page.
Climate temperature data is typically calculated as a 30-year average. This smooths out year-to-year variability and gives a more reliable picture of what a place is actually like, rather than what happened in any single unusual year.
The readings come from a range of sources — land-based weather stations, ocean buoys, ships, and satellites. That data is collected by weather services around the world, then pooled, quality-checked, and averaged to produce the climate records you see here.
Seasonal temperature shifts influence more than just how warm it feels — they also drive changes in rainfall, cloud cover, and wind patterns throughout the year.
Warmer air holds more moisture, which tends to mean heavier or more frequent rain during the warmer months. When temperatures drop in winter, any precipitation that does fall is more likely to come as snow or sleet, though in Rottnest Island this rarely lasts long on the ground.
For more on Rottnest Island's weather — including monthly rainfall, sunshine hours, and humidity — visit our Rottnest Island climate page.
