Frost after Melbourne Cup Day: the odds for 56 Australian towns

What the records show

• 40 of the 56 towns have never had a frosty night after Cup Day in the springs on record, from Sydney and Perth to Mildura and Dubbo. The rule is overcautious there: the last frost usually comes weeks earlier.
• Cooma: a frosty night after Cup Day in 29 of 30 springs (1992–2025). The last one typically comes on 11 December, and the latest on record was 28 December 2004.
• Goulburn: 20 springs of 27, with the last frosty night typically on 18 November.
• Ballarat: 38 springs of 67 since 1957. The recent record is no better: 17 of the 29 springs since 1996.
• Canberra: 36 springs of 71 at the airport's long-running station (1939–2009), the same coin toss ABC News found in 2023. At Tuggeranong, in the south of the city, it was 8 springs of 27 since 1997, the latest on 2 December 2025.
• Orange, Bathurst and Mount Gambier fall between one spring in three and one in two. Mount Gambier has warmed: 30 springs of 84 since 1942, but only 4 of the 30 since 1996.
• Melbourne: 0 springs of 126 at the city station (1889–2014). Its last frosty night typically comes on 12 August, and the latest on record was 22 October 1918. Frost hollows, the outer east and the hills are colder than the city, and inland the risk climbs quickly: Bendigo had a frosty night after Cup Day in about one spring in five.

Frost after Cup Day, town by town

The 16 towns below have had at least one frosty night after Cup Day; Canberra has a row for each of its two stations. Dates are counted from each year's Cup Day and shown for a year when it falls on 3 November, as it does in 2026. "Frost after Cup Day" is the share of springs with a frosty night after the race. "Clear by, 4 in 5" is the date by which the frosts had finished in 80 % of springs, and "Clear by, 19 in 20" the 95 % date.

No frosty night after Cup Day in any spring on record: Adelaide, Albany, Alice Springs, Brisbane, Broken Hill, Broome, Bunbury, Bundaberg, Cairns, Coffs Harbour, Darwin, Dubbo, Esperance, Geelong, Geraldton, Gold Coast, Ipswich, Kalgoorlie, Karratha, Katherine, Lismore, Mackay, Mandurah, Melbourne, Mildura, Mount Isa, Newcastle, Perth, Port Augusta, Port Lincoln, Port Macquarie, Rockhampton, Sunshine Coast, Sydney, Tamworth, Tennant Creek, Toowoomba, Townsville, Whyalla and Wollongong. Download the full table as a CSV file.

What to do with the numbers

• Under 1 spring in 10: Cup Day is a safe planting date, and in most of these towns you can plant weeks earlier. The cool-zone and arid-zone planting calendars give the usual windows.
• 1 spring in 10 to 1 in 3: plant on Cup Day, but keep frost cloth, cloches or an upturned bucket ready, and check the forecast minimum for the next fortnight.
• A third of springs or more: treat Cup Day as the start of the risky period, not the end. Plant on the "Clear by, 4 in 5" date, or plant earlier only with protection you can put out every cold night.

Tomato seedlings need 6–8 weeks from sowing, so count back from your planting date: for a mid-December planting in Cooma, sow indoors in mid-October. The tomato planting guide covers seed, spacing and soil temperature, and capsicum and chilli need even warmer nights.

New Zealand's Labour Weekend

New Zealand's version of the rule is Labour Weekend, which ends on 26 October in 2026. We have no daily station records for New Zealand in this analysis, but NIWA's 1991–2020 averages point the same way: Christchurch still averages 2.6 ground frosts in November and Queenstown 3.9, while Auckland averages none from October. See the southern New Zealand calendar and the tomato guide.

How we worked it out

• Data. Daily minimum temperatures from Bureau of Meteorology weather stations, downloaded from SILO, the Queensland Government's climate database. We kept only the days SILO marks as observed at the station and dropped its interpolated fill-ins.
• A frosty night is a minimum of 2 °C or below. The Bureau's thermometers sit in a screen about 1.2 m above the ground, and on a clear, still night the ground can be several degrees colder, so a 2 °C reading can mean frost on the lawn and on young plants. ABC News used the same threshold.
• Each spring runs from 1 July to 31 December. We found the last frosty night in every spring with at least 95 % of its days observed and compared it with that year's Cup Day, the first Tuesday in November.
• Stations. Each town uses the same Bureau station as the planting calendar, with three exceptions. SILO has no record for the current stations at Albany and Geelong, so those rows use the nearby long-running stations named in the table. Canberra's airport comparison station closed in 2010, so we added Tuggeranong for recent years. Queanbeyan is left out because its station is not in SILO; the Canberra rows cover it.
• Record length varies from 15 to 131 springs, and shorter records are less certain. The table shows the station and years behind every row.
• Check. For Canberra our method gives the same answer as ABC News's 2023 analysis of the airport records: a frosty night after Cup Day in about half of all springs, and the frosts finished by 20 November, 17 days after the race, in 4 springs of 5.

Use this data

The table and the CSV file are free to reuse under the CC BY 4.0 licence, like the Bureau data behind them. Please credit it as "GardenMaths analysis of Bureau of Meteorology data via SILO" and link to this page. If you are writing about a town that isn't listed, ask us and we will run its nearest station.

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