Climate of Mount Isa
The climate of Mount Isa is governed by three main criteria: Tropical location (latitude), elevation and distance from the coast. With the Gulf of Carpentaria approximately 340km to the north, and the Coral Sea 740km to the east-northeast, the climate of Mount Isa is suitably described as ’ Tropical Continental ’.
Three main seasons are experienced in Mount Isa
Mild temperatures with low humidity (MAY to AUGUST)
Night time temperatures in Mount Isa can often be much cooler than those of nearby centres. Mount Isa is located in a valley between two spurs of the Selwyn ranges. On clear nights, the moderate southeasterly winds experienced on the Western Plains and Barkly Tablelands keep the temperature higher. The calm conditions experienced in Mount Isa due to the sheltering effect of the ranges leads to lower temperatures being recorded (this can be up to ten degrees lower in extreme cases).
Due to the continental climate of Mount Isa, the diurnal (daily) temperature range is approximately 10 to 15 degrees throughout the year, although can be as high as 20 to 25 degrees at times. Except for the months of June, July and August, temperatures for the area are described as warm to hot. However, very low minimum temperatures can occur (lowest ever minus 2.9 degrees on the 7th of July 1984) due to the often clear skies experienced in the winter months. Negative temperatures have occurred during the months of June, July and August. Although Mount Isa is just south of the limits of frosts, the area rarely experiences frost conditions to the same degree as continental areas further south.
A failure of the wet season causes severe strain on the
pastures and available surface water supplies. The onset of
drought is greatly enhanced by the high evaporation rates
during the summer months, although the loss during the dry
season is less due to the lower temperatures.
Occasionally, quite heavy and prolonged rain can occur with the passage of ex tropical cyclones, which can lead to an extension south of the monsoon trough from the northern areas of Australia. With it can come flooding of local river and stream systems, with its associated dislocation of local infrastructure.