While Australia had its coldest April in nearly a decade, the rest of the world experienced monthly average temperatures that were the hottest on record, marking eleven straight months of record monthly highs.

Mean temperatures across Australia were 0.51C below the 1961–1990 average, the lowest since 2015, thanks to a high pressure system that arose off Australia’s south-west coast in the middle of the month.

“What we had in April was a blocking high to the south of Australia, which directed cold southerly winds across a huge part of the country,” Weatherzone meteorologist Yoska Hernandez said.

He said the high pressure system blocked warmer air masses from sweeping the south.

“If that blocking high wasn’t there we should have an alternation between [cooler] … and warmer days,” Hernandez said.

“But because the high pressure was there, we did have a continuous and persistent period of cooler winds.”

However, he said, overall we should expect above-average temperatures from April to June, after earlier this year facing the second-warmest March on record for minimum temperatures.

The rest of the world faced the warmest April on record, with average surface air temperatures 0.67C above 1991-2020, leaving the world only one month away from a straight year of record monthly high temperatures.

“Particularly in the northern hemisphere and near the poles and also near parts of Antarctica, it was warmer than average,” Hernandez said, adding that climate change may have influenced global patterns.

While Australia’s blocking high faded last week, the cold streak could continue in May as a new high pressure system develops around the Great Australian Bight.

“Most of this week and most likely into next week, that high will remain over southern parts of Australia, so that will possibly make May cooler than average,” Hernandez said.

The country may also see cooler and wetter conditions persist later in the year as the likelihood of a La Niña increases, with the Bureau of Meteorology forecasting a 50/50 chance the weather pattern will form.