Prosper in a dynamic world
Search

Why Melbourne hit 21°C at 3am last night

Melbourne saw an unusual spike in temperature last night when the mercury jumped to 21°C at 3am, making the middle of the night feel warmer than an average spring day.

Thursday night started off warm for this time of year as light northerly winds had the temperature sitting on 16°C at 10pm. The mercury then cooled to 14°C by midnight, which is about 6°C above the average minimum temperature at this time of year.

A surge of northerly winds then brought much warmer air into the city from central Victoria. By 3am Melbourne’s temperature had shot up to 21°C, a jump of more than 6°C in under three hours.

Image: Northerly winds over central Vic at 4am AEST on Friday, carrying warm inland air towards Melbourne.

It’s rare to see overnight temperatures exceeding 20°C in Melbourne at this time of year:

  • The city’s average minimum temperature in September is 8°C
  • It’s average daytime maximum temperature in September is 17°C
  • The warmest September night on record for Melbourne had a minimum temperature of 20.5°C

Image: Temperature observations in Melbourne during Thursday night and Friday morning, showing abrupt warming between midnight and 3am.

Melbourne has remained warm throughout Friday morning, although cooler southwesterly winds and showers will drop the temperature in the afternoon following the passage of a cold front.

Damaging winds are also likely to affect parts of eastern Vic on Friday ahead of this cold front, so be sure to check the latest severe weather warnings throughout the afternoon.

OpticastTM V5 is Weatherzone’s cloud-based, consensus forecasting solution that delivers precise weather data to your business, both nationally and globally.

Independently verified to significantly outperform other industry models, Opticast gives you a strategic advantage if weather impacts your enterprise. Armed with the most accurate nowcasting and forecasting data, you can mitigate operational and safety risks, and plan to make the most of severe weather windows.

Opticast is powered by machine learning, intelligently adapting to the local conditions of your site area. Gain a world-leading forecasting system that rapidly responds to changing conditions.

We give you the foresight to make quick and powerful decisions when you need to protect your valuable team and assets, and ensure maximum productivity.  For more information, please visit our website or email us at apac.sales@dtn.com.

Latest news

Satisfy your weather obsession with these news headlines from around the nation, and the world.

How does DTN help businesses monitor bushfire induced pyrocumulonimbus thunderstorms that ignite more fires?

Intense heat from bushfires during elevated fire danger days can trigger fire-induced pyrocumulonimbus thunderstorms that ignite additional fires. In early January 2026, an extreme heatwave sweeping over southeastern Australia brought catastrophic fire danger to Victoria. Intensely hot bush and grass fires spread erratically and quickly in hot, dry and gusty winds, with pyrocumulonimbus generating lightning, […]

Active seas to the north and east of Australia disrupting port and maritime operations

Seas to the north and east of Australia are experiencing periods of increased activity this week, leading to disruptions to port, maritime and offshore operations. Intense and hazardous Tasman Sea Ocean conditions across NSW’s South Coast rapidly deteriorated last Friday as a deep feed of easterly winds whipped up large and dangerous seas. The Batemans […]

Transport, emergency and energy industries flooded across Greater Sydney with weekend deluges

Transport, emergency, energy and port industries in eastern NSW and Sydney were impacted by significant flash flooding with intense and heavy rainfall this weekend. Rainfall rates between 80 and 140mm in one to three hours were registered across parts of Sydney’s Northern Beaches and Central Coast on Saturday afternoon and evening. In some areas, these […]

DTN Dangerous Thunderstorm Alerts in action with severe thunderstorms disrupting Perth industries

Severe thunderstorms impacted southwest WA and the Perth region on Sunday, December 14, 2025, triggering Dangerous Thunderstorm Alerts (DTA) by DTN for industries and businesses in the region. DTN operates Dangerous Thunderstorm Alerts (DTA) which alert businesses and industries to thunderstorms based on intensity and movement. These alerts provide advanced notice of thunderstorms moving into […]