Cold snap breaks May temperature records across Victoria

Coldstream, in the Yarra Valley northeast of Melbourne, recorded Victoria’s lowest temperature during this cold snap, registering -5.5°C (22.1°F) on Tuesday, May 20. This set a new May minimum record at the site, surpassing Monday’s reading of -5.3°C (22.5°F), which had already broken the 30-year station record.

Interestingly, Coldstream remained colder than alpine locations, including Mt Hotham, which reached -4.9°C (23.2°F).

In Morwell, eastern Victoria, the temperature dropped to -3.9°C (25.0°F), its lowest May reading in 42 years of observations. Kanagulk, a rural locality in the Wimmera, recorded -4.1°C (24.6°F), its coldest on record since the site’s establishment in 2004. Ballarat registered -3.0°C (26.6°F), marking its first sub-zero reading of 2025 and its coldest night of the year so far.

The Bureau of Meteorology (BOM) issued frost warnings across all nine Victorian forecast districts, cautioning motorists about icy roads and reduced early morning visibility. The widespread frost was attributed to a dominant high-pressure system, clear skies, and dry surface conditions, which allowed for efficient overnight radiative cooling.

South Australia’s minimum was recorded at Coonawarra in the Lower South East forecast district, where temperatures fell to -4.7°C (23.5°F), the coldest May reading in 60 years and the lowest for any month in 43 years.

Tarcoola in the North West Pastoral region reported -2.5°C (27.5°F), breaking its previous May record of -1.6°C (29.1°F), based on records dating back to 1903.

Ceduna recorded 0.3°C (32.5°F) and Whyalla 0.6°C (33.1°F), both unusually low for coastal towns in South Australia during May.

A Frost Warning is in place for the Mallee, Wimmera, Northern Country, North Central, North East, South West, Central, West and South Gippsland, and East Gippsland forecast districts of Victoria for Wednesday, May 21.

Severe frosts with temperatures down to -3°C (26.6°F), which can cause significant crop damage, are expected in parts of the North Central, North East, Central, and West and South Gippsland districts.

Frosts with minimum temperatures down to -2°C (28.4°F) are forecast for parts of the Mallee, Wimmera, Northern Country, South West, and East Gippsland districts.

BOM warns that actual ground-level temperatures may be several degrees lower than those recorded at standard weather stations, especially under calm and clear overnight conditions.

References:

¹ Big dry contributes to record cold SA, Vic mornings – weatherzone – May 20, 2025