Lead

Melbourne and much of Victoria are experiencing a prolonged spell of summer-like weather, with temperatures on May 1 breaking records across the state and a high-pressure system expected to keep conditions stable into the coming weeks.

On the first day of May, Avalon and Geelong tied as the warmest places in the state, reaching 29.3 degrees Celsius, according to the Bureau of Meteorology (BOM). At least 20 locations saw their warmest May day on record, with records set in areas as varied as Nhill, Horsham, Portland, Colac, Bendigo, Morwell, Shepparton and Aireys Inlet.

Coverage Comparison

ABC Australia reported that the unseasonable warmth is being driven by a high-pressure system lingering over the Tasman Sea, which has been directing northerly winds across Victoria. The system has also been linked to a broader stagnation in Australia's weather patterns, with seven-day forecasts showing little variation across many parts of the country.

A separate ABC report notes that Melbourne is on track to record its longest run of April days above 20 degrees Celsius in more than a decade. BOM senior meteorologist David Crock said the month was expected to end with an 11-day run above 20°C, and that the pattern could continue into early May, potentially reaching two weeks.

Key Claims

  • Record May temperatures: At least 20 locations across Victoria recorded their warmest May day on record on May 1, with Avalon, Geelong and Walpeup reaching 29.3°C. Other notable readings included Melbourne Airport at 27.1°C, Essendon at 27°C, and Moorabbin at 28.1°C.
  • Cause: The warm conditions are attributed to a high-pressure system (a "blocking high") parked over the Tasman Sea, which is deflecting cooler weather away from south-eastern Australia and directing warm northerly winds across Victoria.
  • Forecast: A cold front is expected to move into Victoria on Saturday night and Sunday, bringing a band of rain and strong winds, which could end the current warm spell.
  • Duration of the blocking high: The high-pressure system has stalled over the Tasman Sea and is expected to remain in place for at least another week, potentially leading to a stagnation lasting up to a fortnight.
  • Melbourne's April run: Melbourne is set to record its longest run of April days above 20°C in more than a decade, with 11 consecutive days expected by the end of April, potentially stretching into early May.
BOM senior meteorologist Dean Narramore noted that the temperatures were about 10 to 14 degrees above average for this time of year, more typical of February or March. He added that warm northerly winds could lead to record warm May nights as well, particularly in western and south-western Victoria.

The blocking high has also caused a split in the polar and sub-tropical jet streams over eastern Australia, contributing to the stagnant pattern. While most such systems last only a few days, the current one may persist for up to a fortnight, removing the usual day-to-day variability in weather.

Despite the warmth, temperatures have been cooler in parts of Gippsland, where onshore easterly winds have kept conditions more moderate. The settled weather has been beneficial for planned burning programs carried out by firefighting agencies, according to Crock.

As the warm spell continues, residents are advised to enjoy the summery conditions while they last, as a cold front is expected to bring cooler weather and rain over the weekend.