The Cape York region is situated at the northern tip of
Queensland in a tropical climatic zone where summers are wet and
winters are comparatively dry (Bureau of Meteorology 1989). Coastal
climatic effects are pronounced in this region as it is bordered by
the Gulf of Carpentaria to the west and the Coral Sea to the
Summers are hot with maximum temperatures around
33-36ºC in January. The coolest temperatures are experienced
along the coast and to the east (Colls & Whitaker 1990).
Humidity is high, averaging 60-80 per cent, across the region with
southern inland readings lowest. Climate discomfort days range from
only 50 along the north and east coasts to 150 in the south-west
(Bureau of Meteorology 1989) in close association with temperature
gradients. Even though this region averages seven to eight hours'
sunshine each day, it is one of the cloudiest in the savannas
(Colls & Whitaker 1990).
North-west monsoons bring heavy summer rains which in
combination with the moist south-easterly trade winds combine to
shed an annual average of 800 mm in the south to a prolific 2400 mm
in the north. In inland regions more than 90 per cent of this rain
falls in summer whereas only around 75 per cent falls as summer
rain along the coast. There is only low to moderate variability in
this rainfall (Bureau of Meteorology 1989) with droughts less
likely to occur in the north (Colls & Whitaker
Tropical cyclones are associated with the most widespread, heavy
rainfalls followed by thunderstorms and monsoon depressions
(Gentilli 1972). Thunderstorms occur less frequently here than in
other regions with an annual average of as few as 20 thunder days
along the coast to perhaps twice that many inland (Bureau of
Meteorology 1989). In La Nina years rainfall increases across the
entire region in an east-west direction (Partridge 1991).
After the summer rains ease and the south-east trade winds
become established relative humidity can fall to 30 per cent by
July but in some areas along the eastern coast it may linger around
80 per cent (Colls & Whitaker 1990). Winter rainfall can be
associated with the moist trade winds being uplifted over the
coast. Temperatures moderate in winter with July average minimums
dropping to 21ºC in the north and 15ºC in the southern
inland areas (Colls & Whitaker 1990).