May and June are the hottest places in our country.
This summer hasn’t just felt hot. It’s been hot. In fact, the summer of 2012-13 is now the hottest on record. Average temperatures beat the record set in the summer of 1997-98, and daytime maximum temperatures knocked over the 1982-83 record. January 2013 has been the hottest month since records began in 1910.
A significant summer, for weather and climate
There is an old adage in meteorology and climatology circles, “Climate is what you expect, weather is what you get”. But what does this mean?
Essentially, climate is a statistical description of weather. It describes the average weather experienced over a period of time — over either a single location, or averaged over a large region. Climate also describes how variable the weather is around those averages.
Climate also describes trends — longer-term changes in weather that are distinct from the shorter-term variability.
When it comes to climate change, there is often confusion as to when one should consider a particular meteorological event to be “just weather” or something more significant in a climatological context.
In general, the individual weather and climate events that scientists consider most significant are those that are both at the extremes of — or beyond — our historical experience, and consistent with quantifiable trends.
In that context, the summer of 2012-13 has had it all.
As far as day-to-day weather goes, numerous individual locations in Australia set daytime records for extreme heat. As far as regional averages go, records were also set for the hottest daytime temperatures averaged over the whole of Australia.
Records were set for the duration of extreme heat at both individual locations, and for Australia as a whole. Birdsville experienced 31 successive days above 40°C and Alice Springs had 17.
When it comes to averages over time, January 2013 was the hottest month recorded in the entire observational record for Australia, stretching back to 1910 (the first year for which we can confidently estimate national temperatures).