Last month was a scorcher for global temperatures with warmth over land and sea breaking records for June while sea-surface temperatures posted their largest departure from long-term averages for any month.
Combined average land and sea temperatures were 0.72 degrees above the 20th century average of 15.5 degrees, making it the hottest June. It adds to the record May and equal record April, according to the US National Oceanic and Atmospheric Administration (NOAA).
More striking for climatologists, though, were the sea-surface temperatures. These came in 0.64 degrees above the 20th century average of 16.4 degrees – the first time any month had exceeded the long-run norm by more than 0.6 degrees.
Parts of all major ocean basins notched their warmest June, with almost all the Indian Ocean and regions off south-eastern Australia the hottest on record.
An El Nino event remains about a 70 per cent chance of forming during the northern summer, which could lead to more records. The weather pattern sees the central and eastern equatorial Pacific Ocean becoming relatively warm compared with western regions, and typically brings hotter, drier-than-usual conditions to south-east Asia and Australia.
Australia posted its hottest 12 months on record in the year to June, and the warmth has continued well into July for many regions, including for Sydney.
So far this year, above-average maximums in Sydney are running at about 2.5-to-one compared with cooler-than-usual weather, according to the Bureau of Meteorology.
In the first half of the year, Sydney had 162 days of 20 degrees or warmer conditions, beating the previous record in 2004 of 157.
Following Tuesday's 19-degrees top and 16 expected for Wednesday, Sydney can expect a string of warm days to end the month, including a high of 22 degrees on Friday.
"It's going to be pretty nice in Sydney – not particularly mid-winter-like at all," said Rob Sharpe, a meteorologist with Weatherzone.
With just 4 millimetres of rain recorded so far, July is also on course to be among Sydney's driest for this time of year. If there are no further falls at Observatory Hill, it will be the driest July since 1970, Mr Sharpe said.
Those warm and dry conditions – with only November recording above-average rainfall in the past year for Sydney – are likely to continue if an El Nino takes hold in the Pacific, Mr Sharpe said.
Globally, June was the 352nd month when global temperatures were above the 20th century average – with the last below-average month in February 1985 when Bob Hawke was in his first term as prime minister and Ronald Reagan in his second term in the White House.
