Vapour pressure

According to the American Meteorological Society's Glossary of Meteorology, vapour pressure is the pressure exerted by the molecules of a given vapour. For a pure, confined vapour, it is that vapour's pressure on the walls of its containing vessel; for a vapour mixed with other vapours or gases, it is that vapour's contribution to the total pressure (i.e., its partial pressure). In meteorology, vapour pressure is used almost exclusively to denote the partial pressure of water vapour in the atmosphere.

The water vapour pressure is directly related to the number of water vapour molecules in the air. In Australia, the air-masses with the highest water vapour content are tropical in origin, while those with the lowest are sourced from the arid interior or the high latitudes of the Southern Ocean during cold outbreaks.

Humans experience the sensation of "humidity" when the vapour pressure reaches around 18 to 20 hPa, allowing for individual tolerances and acclimatisation to local conditions. Furthermore, the air can feel "humid" despite the fact that the relative humidity doesn't convey it. For example, at 3 pm on an average January day in Broome, the relative humidity would be about 66%, but the vapour pressure would be around 30 hPa. Conversely, on a cool, foggy morning in Hobart with a temperature of, say, 5°C, the relative humidity will be 100% but the vapour pressure would only be around 9 hPa.

http://www.bom.gov.au/climate/austmaps/about-vprp-maps.shtml

Rainfall
http://www.bom.gov.au/climate/austmaps/about-rain-maps.shtml

Temp
http://www.bom.gov.au/climate/austmaps/about-temp-maps.shtml

Solar Exposure
http://www.bom.gov.au/climate/austmaps/about-solar-maps.shtml