October was one of the wettest on record in Canberra, with most sites receiving at least double their long-term average and the Canberra Airport station recording its wettest October in 44 years.
Tuggeranong had its highest total October rainfall on record, while some sites had their highest total October rainfall for at least 20 years.
Bureau of Meteorology forecaster Jordan Notara said Canberra Airport recorded 133.6 millimetres of rain during October, breaking the 2010 record of 102.8 mm.
“There were a whole bunch of records broken in the region for the month of October. A lot of the records are 10 years of data but this month is definitely the most notable of rain that’s occurred,” he said.
Records at the current Canberra Airport date back to 2010, while the previous October record taken from a nearby site saw 161 mm of rainfall in 1976.
Rain fell on 15 out of 31 days in October, with the highest falls coming on the last two days of the month (30 and 31 October) when more than 40 mm of rain fell. However, precise figures are inaccurate because October rainfall for the month ends at 9:00 am on 31 October, while rain recorded after 9:00 am is counted in November’s figures.
There were numerous significant rain events during the month, with seven days when 10 mm or more fell at Canberra Airport, which equalled the record for any month set in December 1947, March 1950 and February 2002. There were also 10 days with 5 mm or more which was the most in any month since March 1956.
Some stations recorded eight days of straight rainfall between 24 and 31 October.
October was also a month of thunderstorms, particularly between 15 and 17 October, and again from 23 October onwards, although most of the storms did not reach severe criteria.
Canberra has now exceeded its average annual rainfall, with 655.4 mm to the end of October. The total for the year to date is 33 per cent above average, but slightly below the 666.8 mm recorded to the end of October in 2016.
Mr Notara said the records are similar to 2010 which was also a La Niña year, during which high levels of winter and spring rainfall are triggered across the north and east of Australia.
The severe floods of 1955, 1988, 1998 and 2010 were all associated with La Niña events.
October’s total rainfall for Canberra Airport of 133.6 mm was 224 per cent higher than the long-term average of 59.7 mm.
Minimum temperatures were also well above average, while daytime maximum temperatures were close to average.
Maximum temperatures at Canberra Airport for the year-to-date are 0.5 °C above average, which is the lowest since 2011, while minimum temperatures are 1.1 °C above average.
The average daily maximum temperature for Canberra Airport was 20.3 °C, which is 0.6 °C above the long-term average of 21.7°C.
The warmest day was 26.4°C on 23 October and the coolest day was on 26 October when the temperature reached 12.8°C.
The average daily minimum temperature for Canberra Airport was 8.8°C, which is 2.8°C above the long-term average of 6.0°C, and the second-warmest on record after 9.0°C in 1973.
The coldest morning was 1.2°C on 2 October, the first October since 2005 when it has not fallen below 1°C. The warmest morning was on 24 October when the minimum temperature was 15.5°C.
Tuggeranong also recorded its highest daily minimum temperature October night on record of 15.7 °C on 24 October.
The Territory now gets a few days to dry out ahead of the next rainfall which is predicted to fall on Thursday. Wednesday will see a forecast maximum of 27 before the temperature drops back almost 10 degrees on Thursday.
“However, we won’t be seeing the heavy falls again that we saw from last weekend,” Mr Notara said.