Climate of Albany

Albany has a Mediterranean-type climate with generally warm summers and cool, wet winters. The city is situated on what is promoted as the “Rainbow Coast” which is an appropriate title given the significant frequency of cool cloudy days with drizzle or showers.

The Bureau of Meteorology has records of rainfall observations for Albany dating back to 1877 and general weather observations back to 1880. Weather observations at the Albany Post Office ceased in 1965 as observations by Bureau staff commenced at the Meteorological Office at Albany Airport, which is located approximately 12 kilometres to the northwest of the city centre. After an absence of more than 30 years, weather observations near the city centre recommenced in 2002 at the museum, next to Princess Royal Harbour.

A major factor influencing Albany’s climate is the Southern Ocean. The city is situated on the southern coast of WA and the ocean imparts a moderating influence via sea breezes in the warmer months and more generally through the effects of a relatively mild and moist airmass at any time of the year. Another significant factor is the position of a band of high pressure known as the sub-tropical ridge, and seasonal variations are mainly due to the north-south movement of this ridge. An easterly broadscale flow prevails in summer when the ridge is south of the State, however the movement of high pressure cells from west to east along this ridge brings a commonly repeated pattern of wind changes to south coast locations. Albany’s south coast aspect means that the progression of winds from east through north, west, south and returning to east over periods of several days to a week or more during summer can bring a large variation in weather from fine and mild, to hot with thundery showers, to cool and cloudy with drizzle. When the ridge moves north in the cooler months, the moisture-laden westerly winds south of the ridge deliver much of Albany's annual rainfall. Atmospheric disturbances embedded in the westerlies are common in the winter months with sometimes several cold fronts passing through southwest WA in a week.

Albany's long-term median annual rainfall is approximately 930 mm though there can be considerable variation in the total rainfall from year to year. Annual rainfall has ranged from 1395.2 mm in 1955 to 628.5 mm in 1972. On average, approximately 72 per cent of the annual rainfall occurs between May and October. Although cold fronts are responsible for much of the recorded rainfall total, a moist onshore flow can occur in any season and bring showers or drizzle. Thus Albany records rainfall on 178 days annually, on average, which equates to almost one day in every two.

July is the wettest month, with a long-term average of over 140 mm, whilst rain occurs on two days out of every three during an average winter. The driest month is February with a mean of about 23 mm and in summer it rains on average about one day in every four.

Like other parts of southwest WA, winter rainfall has decreased in Albany during the latter half of the twentieth century. Evidence suggests that both natural variability and the enhanced greenhouse effect have most likely contributed to this decrease.

Average maximum temperatures peak in January and February in Albany, with monthly means of almost 23°C although temperatures above 35°C sometimes occur when hot, dry northerly winds arrive from the interior of WA. Overnight minima also peak in January and February at a mild 15°C, on average.

Winter daily maximum temperatures average approximately 16°C, while the average minimum is approximately 8°C in July and August. Daily minimum temperatures below 5°C can be expected about once or twice a month in winter, but Albany daily temperature records between 1907 and 1965 show no occasion where the temperature fell to zero. At Albany Airport, temperatures at or below zero have been recorded on only two occasions between 1965 and 2002.

Albany experiences quite a varied wind climate with a bias toward an easterly wind component in summer and a westerly component in winter. Interestingly, on average, the windiest part of the day during winter is the morning and in summer is the afternoon. Spring and summer afternoon sea breezes are regularly experienced from directions from the southwest through to the east, however sea breezes from the southeast or east are most common. Summer sea breezes are frequently quite fresh and sometimes reach 25 knots (46 km/h) or more. Late autumn, winter and early spring see regular northwesterly morning winds due to a combination of the sub-tropical ridge being located to the north of Albany, with a high centre over the continent, and a land-breeze effect. Cold fronts with winter westerlies are regular visitors to Albany during this period, and bring strong to gale force winds at times.

Recording of daily sunshine hours has commenced relatively recently at Albany Airport. A little less than ten years of recording indicates that the maximum mean daily sunshine hours occurs in January at just over 8 hours and reduces to a minimum in June of about 5 hours. Monthly average values show a gradual decline after January and a gradual increase after June, giving an annual mean of approximately 6.5 hours per day.

The average annual pan evaporation at Albany Airport is just under 1390 mm and the mean daily figure ranges from just under 2 mm in June to almost 7 mm in January. Daily pan evaporation can range from zero on a cold, wet winter's day to around 15 mm on a hot, blustery summer's day. Within an area such as Albany, however, with its diverse topography, the average evaporation can vary significantly even over short distances.