November 2018 is likely to be the first month of what will be an El Nino year, though it’s difficult to say whether this is the sole cause of the heatwave and it’s likely we saw a combination of factors come together to generate the heat.
Traditionally westerly winds along the Queensland coastline are quite rare during the warmer months of the year, but can happen further south in southern Queensland which is more prone to the impacts of mid-latitude systems that may generate these westerly winds. Normally the warmer months are marked by warm and humid southeast or northeast winds. While temperatures are still often hot and muggy, they seldom approach the high 30s let alone reaching 40C along the coast in central to north Queensland. It was these strong, westerly winds that have also been responsible for the horror fire conditions that have since plagued the state.
During winter, westerly winds are more common but during winter the interior of the country is quite cool so many residents associate westerly winds with cooler conditions. It’s different in the leadup of summer where temperatures across the interior are much hotter meaning westerly winds during (and around) summer produce hot conditions.