Australia's hottest ever summer

It's been a beast of a summer in Australia.  Intense, unrelenting heat, drought, fires here in the south and 1 in 1000 year floods in the north.  And if you're Ozzie and you thought this was a very hot summer, you were right.  It was the hottest ever.

From The Guardian:

Australia has endured its hottest summer ever, according to the Bureau of Meteorology, breaking the previous record set six years ago.

The 2018-19 summer, which produced near 50C days and topped temperature highs across the country, has officially exceeded the previous record set in 2012-13, which was 1.28C above what is considered normal. Climate analysts say it falls into a pattern of human-induced global warming.

January alone had already been confirmed as the hottest month ever recorded in Australia, with a mean temperature across the nation of 30.8C, which was 2.9C above the average for January temperatures (calculated between 1961–1990) of 27.9C.

While exact figures are not yet confirmed, the bureau said this summer’s mean temperature was at least 2C above the 27.5C benchmark of what is considered normal, based on 1961-1990.

“Summer has been our warmest summer on record in terms of maximum temperatures, in terms of minimum temperatures and in terms of mean temperatures,” said Andrew Watkins, the BoM’s manager of long-range forecasting.

The statistics will come as no surprise to Australians who sweltered through back-to-back heatwaves and battled bushfires across the country.

In January alone, Adelaide broke its all-time heat record with a 46.6C day, Port Augusta broke its record with 48.9C, and then broke it again with 49.5C a week later.

The small New South Wales town of Noona also broke the record for the highest overnight minimum ever recorded, with a night that never dropped below 39.5C. And in Cloncurry in Queensland, residents endured 43 days in a row over 40C, Watkins said.

This summer’s extreme temperatures had been predicted since late last year, with the BoM’s climate outlook forecasting a drier, hotter summer due to the El Niño weather event, a positive Indian Ocean Dipole and the effect of global warming.

The “long-term increasing trend in global air and ocean temperatures” was a factor in the hotter-than-average summer, the report said in October.

[Read more here]

Just as with the record warmth in February in the UK, a record hot summer is not by itself proof of global warming.  But a sequence of record new highs for temperature, a sequence of ever higher lows, a long trend of rising 5 or 10 year averages is.  But ordinary people, who don't know much about statistics, aren't convinced by warmer than normal winters.  After all, it's still cold, right?  But day after day of unrelenting, extraordinary heat in summer does tend to convince.

In my opinion, the chart below should be enough.  It shows a five year moving average of  NOAA's calculation of the global temperature anomaly relative to the 1901-2000 average.  Even a 5 year moving average shows some cycles.  But the trend is clearly up.  In that context, new record highs are no longer just random events.  They're part of the pattern.  And even Joe Public is noticing.

Source: NOAA