Average Weather at Perth Airport Australia
At Perth Airport, the summers are hot and dry; the winters are long, cool, and wet; and it is windy and mostly clear year round. Over the course of the year, the temperature typically varies from 47°F to 89°F and is rarely below 39°F or above 100°F.
Based on the tourism score, the best time of year to visit Perth Airport for warm-weather activities is from late November to early April.
The hot season lasts for 3.0 months, from December 18 to March 20, with an average daily high temperature above 83°F. The hottest day of the year is January 29, with an average high of 89°F and low of 65°F.
The cool season lasts for 4.0 months, from May 26 to September 26, with an average daily high temperature below 68°F. The coldest day of the year is July 19, with an average low of 47°F and high of 63°F.
Average High and Low Temperature
The figure below shows you a compact characterization of the entire year of hourly average temperatures. The horizontal axis is the day of the year, the vertical axis is the hour of the day, and the color is the average temperature for that hour and day.
Average Hourly Temperature
Chatsworth, California, United States (9,323 miles away) and Sidi Yahia El Gharb, Morocco (9,148 miles) are the far-away foreign places with temperatures most similar to Perth Airport (view comparison).
At Perth Airport, the average percentage of the sky covered by clouds experiences mild seasonal variation over the course of the year.
The clearer part of the year at Perth Airport begins around August 20 and lasts for 7.0 months, ending around March 18. On January 19, the clearest day of the year, the sky is clear, mostly clear, or partly cloudy 86% of the time, and overcast or mostly cloudy 14% of the time.
The cloudier part of the year begins around March 18 and lasts for 5.0 months, ending around August 20. On April 18, the cloudiest day of the year, the sky is overcast or mostly cloudy 31% of the time, and clear, mostly clear, or partly cloudy 69% of the time.
Cloud Cover Categories
0% clear 20% mostly clear 40% partly cloudy 60% mostly cloudy 80% overcast 100%
A wet day is one with at least 0.04 inches of liquid or liquid-equivalent precipitation. The chance of wet days at Perth Airport varies significantly throughout the year.
The wetter season lasts 4.6 months, from May 8 to September 26, with a greater than 23% chance of a given day being a wet day. The chance of a wet day peaks at 42% on July 22.
The drier season lasts 7.4 months, from September 26 to May 8. The smallest chance of a wet day is 4% on December 28.
Among wet days, we distinguish between those that experience rain alone, snow alone, or a mixture of the two. Based on this categorization, the most common form of precipitation throughout the year is rain alone, with a peak probability of 42% on July 22.
Daily Chance of Precipitation
To show variation within the months and not just the monthly totals, we show the rainfall accumulated over a sliding 31-day period centered around each day of the year. Perth Airport experiences extreme seasonal variation in monthly rainfall.
The rainy period of the year lasts for 10 months, from January 15 to November 29, with a sliding 31-day rainfall of at least 0.5 inches. The most rain falls during the 31 days centered around July 8, with an average total accumulation of 4.5 inches.
The rainless period of the year lasts for 1.5 months, from November 29 to January 15. The least rain falls around December 21, with an average total accumulation of 0.3 inches.
Average Monthly Rainfall
The length of the day at Perth Airport varies significantly over the course of the year. In 2019, the shortest day is June 21, with 10 hours, 4 minutes of daylight; the longest day is December 22, with 14 hours, 15 minutes of daylight.
Hours of Daylight and Twilight
The earliest sunrise is at 5:02 AM on December 5, and the latest sunrise is 2 hours, 14 minutes later at 7:17 AM on July 2. The earliest sunset is at 5:18 PM on June 11, and the latest sunset is 2 hours, 8 minutes later at 7:26 PM on January 9.
Daylight saving time (DST) is not observed at Perth Airport during 2019.
Sunrise & Sunset with Twilight
We base the humidity comfort level on the dew point, as it determines whether perspiration will evaporate from the skin, thereby cooling the body. Lower dew points feel drier and higher dew points feel more humid. Unlike temperature, which typically varies significantly between night and day, dew point tends to change more slowly, so while the temperature may drop at night, a muggy day is typically followed by a muggy night.
The perceived humidity level at Perth Airport, as measured by the percentage of time in which the humidity comfort level is muggy, oppressive, or miserable, does not vary significantly over the course of the year, staying within 3% of 3% throughout.
Humidity Comfort Levels
dry 55°F comfortable 60°F humid 65°F muggy 70°F oppressive 75°F miserable
This section discusses the wide-area hourly average wind vector (speed and direction) at 10 meters above the ground. The wind experienced at any given location is highly dependent on local topography and other factors, and instantaneous wind speed and direction vary more widely than hourly averages.
The average hourly wind speed at Perth Airport experiences mild seasonal variation over the course of the year.
The windier part of the year lasts for 4.6 months, from November 1 to March 22, with average wind speeds of more than 12.3 miles per hour. The windiest day of the year is January 24, with an average hourly wind speed of 13.7 miles per hour.
The calmer time of year lasts for 7.3 months, from March 22 to November 1. The calmest day of the year is May 1, with an average hourly wind speed of 10.9 miles per hour.
Average Wind Speed
The predominant average hourly wind direction at Perth Airport varies throughout the year.
The wind is most often from the east for 4.1 months, from February 8 to June 11, with a peak percentage of 45% on March 6. The wind is most often from the west for 3.7 months, from June 11 to October 2, with a peak percentage of 42% on September 7. The wind is most often from the south for 4.2 months, from October 2 to February 8, with a peak percentage of 48% on January 1.
Perth Airport is located near a large body of water (e.g., ocean, sea, or large lake). This section reports on the wide-area average surface temperature of that water.
The average water temperature experiences some seasonal variation over the course of the year.
The time of year with warmer water lasts for 3.9 months, from January 15 to May 12, with an average temperature above 71°F. The day of the year with the warmest water is March 6, with an average temperature of 72°F.
The time of year with cooler water lasts for 3.3 months, from July 30 to November 7, with an average temperature below 67°F. The day of the year with the coolest water is September 20, with an average temperature of 65°F.
Average Water Temperature
Best Time of Year to Visit
To characterize how pleasant the weather is at Perth Airport throughout the year, we compute two travel scores.
The tourism score favors clear, rainless days with perceived temperatures between 65°F and 80°F. Based on this score, the best time of year to visit Perth Airport for general outdoor tourist activities is from late November to early April, with a peak score in the third week of January.
The beach/pool score favors clear, rainless days with perceived temperatures between 75°F and 90°F. Based on this score, the best time of year to visit Perth Airport for hot-weather activities is from early January to early March, with a peak score in the second week of February.
For each hour between 8:00 AM and 9:00 PM of each day in the analysis period (1980 to 2016), independent scores are computed for perceived temperature, cloud cover, and total precipitation. Those scores are combined into a single hourly composite score, which is then aggregated into days, averaged over all the years in the analysis period, and smoothed.
Our cloud cover score is 10 for fully clear skies, falling linearly to 9 for mostly clear skies, and to 1 for fully overcast skies.
Our precipitation score, which is based on the three-hour precipitation centered on the hour in question, is 10 for no precipitation, falling linearly to 9 for trace precipitation, and to 0 for 0.04 inches of precipitation or more.
Our tourism temperature score is 0 for perceived temperatures below 50°F, rising linearly to 9 for 65°F, to 10 for 75°F, falling linearly to 9 for 80°F, and to 1 for 90°F or hotter.
Our beach/pool temperature score is 0 for perceived temperatures below 65°F, rising linearly to 9 for 75°F, to 10 for 82°F, falling linearly to 9 for 90°F, and to 1 for 100°F or hotter.
Definitions of the growing season vary throughout the world, but for the purposes of this report, we define it as the longest continuous period of non-freezing temperatures (≥ 32°F) in the year (the calendar year in the Northern Hemisphere, or from July 1 until June 30 in the Southern Hemisphere).
Temperatures at Perth Airport are sufficiently warm year round that it is not entirely meaningful to discuss the growing season in these terms. We nevertheless include the chart below as an illustration of the distribution of temperatures experienced throughout the year.
Time Spent in Various Temperature Bands and the Growing Season
Growing degree days are a measure of yearly heat accumulation used to predict plant and animal development, and defined as the integral of warmth above a base temperature, discarding any excess above a maximum temperature. In this report, we use a base of 50°F and a cap of 86°F.
Growing Degree Days
This section discusses the total daily incident shortwave solar energy reaching the surface of the ground over a wide area, taking full account of seasonal variations in the length of the day, the elevation of the Sun above the horizon, and absorption by clouds and other atmospheric constituents. Shortwave radiation includes visible light and ultraviolet radiation.
The average daily incident shortwave solar energy experiences extreme seasonal variation over the course of the year.
The brighter period of the year lasts for 3.4 months, from November 4 to February 17, with an average daily incident shortwave energy per square meter above 7.6 kWh. The brightest day of the year is December 28, with an average of 8.8 kWh.
The darker period of the year lasts for 3.6 months, from May 2 to August 21, with an average daily incident shortwave energy per square meter below 3.9 kWh. The darkest day of the year is June 23, with an average of 2.6 kWh.
Average Daily Incident Shortwave Solar Energy
For the purposes of this report, the geographical coordinates of Perth Airport are -31.940 deg latitude, 115.967 deg longitude, and 66 ft elevation.
The topography within 2 miles of Perth Airport contains only modest variations in elevation, with a maximum elevation change of 164 feet and an average elevation above sea level of 65 feet. Within 10 miles contains only modest variations in elevation (1,276 feet). Within 50 miles contains very significant variations in elevation (2,054 feet).
The area within 2 miles of Perth Airport is covered by artificial surfaces (61%), sparse vegetation (24%), and trees (12%), within 10 miles by artificial surfaces (42%) and trees (38%), and within 50 miles by water (30%) and trees (29%).
This report illustrates the typical weather at Perth Airport, based on a statistical analysis of historical hourly weather reports and model reconstructions from January 1, 1980 to December 31, 2016.
Temperature and Dew Point
Perth Airport has a weather station that reported reliably enough during the analysis period that we have included it in our network. When available, historical temperature and dew point measurements are taken directly from this weather station. These records are obtained from NOAA's Integrated Surface Hourly data set, falling back on ICAO METAR records as required.
In the case of missing or erroneous measurements from this station, we fall back on records from nearby stations, adjusted according to typical seasonal and diurnal intra-station differences. For a given day of the year and hour of the day, the fallback station is selected to minimize the prediction error over the years for which there are measurements for both stations.
All data relating to the Sun's position (e.g., sunrise and sunset) are computed using astronomical formulas from the book, Astronomical Tables of the Sun, Moon and Planets , by Jean Meeus.
All other weather data, including cloud cover, precipitation, wind speed and direction, and solar flux, come from NASA's MERRA-2 Modern-Era Retrospective Analysis . This reanalysis combines a variety of wide-area measurements in a state-of-the-art global meteorological model to reconstruct the hourly history of weather throughout the world on a 50-kilometer grid.
Land Use data comes from the Global Land Cover SHARE database , published by the Food and Agriculture Organization of the United Nations.
Elevation data comes from the Shuttle Radar Topography Mission (SRTM) , published by NASA's Jet Propulsion Laboratory.
Names, locations, and time zones of places and some airports come from the GeoNames Geographical Database .
Time zones for aiports and weather stations are provided by AskGeo.com .
Maps are © Esri, with data from National Geographic, Esri, DeLorme, NAVTEQ, UNEP-WCMC, USGS, NASA, ESA, METI, NRCAN, GEBCO, NOAA, and iPC.
The information on this site is provided as is, without any assurances as to its accuracy or suitability for any purpose. Weather data is prone to errors, outages, and other defects. We assume no responsibility for any decisions made on the basis of the content presented on this site.
We draw particular cautious attention to our reliance on the MERRA-2 model-based reconstructions for a number of important data series. While having the tremendous advantages of temporal and spatial completeness, these reconstructions: (1) are based on computer models that may have model-based errors, (2) are coarsely sampled on a 50 km grid and are therefore unable to reconstruct the local variations of many microclimates, and (3) have particular difficulty with the weather in some coastal areas, especially small islands.
We further caution that our travel scores are only as good as the data that underpin them, that weather conditions at any given location and time are unpredictable and variable, and that the definition of the scores reflects a particular set of preferences that may not agree with those of any particular reader.