One of the most severe hailstorms recorded in Canberra in the Australian Capital Territory (ACT) occurred on Monday 20 January 2020. Hail of four to six centimetres in diameter fell across a region extending from the southern half of Belconnen north-west of the city centre, through Acton to the inner southern suburbs.
In the same storm, Canberra Airport reported a wind gust of 117 kilometres per hour, its strongest since 1996 and the second-strongest on record in the ACT for January.
A warning was issued before the storm by the Bureau of Meteorology for "damaging, locally destructive winds, large, possible giant hailstones and heavy rainfall that may lead to flash flooding" and advising residents to move cars undercover and stay indoors. The storm was expected to hit the city at about 12:30pm.
The storm arrived in the early afternoon and lasted just 15 minutes, but more than 1,000 homes lost power, with outages reported in Florey, Griffith, Deakin and Kambah, and dozens of other suburbs across the city. Other areas suffered damage from hailstones and very strong winds including Belconnen, the city, the Australian National University and several inner southern suburbs.
Widespread damage included fallen trees, branches and power lines, blocked roads, broken windows and sky lights in homes and commercial buildings, flooding, and thousands of cars damaged by hailstones. The CSIRO was among the worst-hit institutions, where 65 glasshouses were damaged and two to three years of research was lost, most aimed at improving crop sustainability by reducing the amount of water, chemical and fertiliser needed.
The National Museum of Australia was forced to close due to structural damage and the Australian National University issued a “shelter in place” alert and closed for a day. Several species of wildlife were severely affected, including more than 300 flying foxes, a protected species, that were killed by hailstones and falling trees.
The Emergency Services Agency (ESA) received approximately 2100 requests for assistance, and the ACT Ambulance Service treated two people for minor injuries sustained during the storm.
This record number of requests occurred during protracted ESA operations in response to bushfires that had been burning in New South Wales (NSW) for several weeks, and required incident management team (IMT) staff and on-ground emergency responders to be reallocated to the hailstorm. More than 300 ACT State Emergency Service (SES) members, assisted by NSW SES, Transport Canberra and City Services, the Australian Defence Force and ACT Fire & Rescue responded to calls for help throughout the afternoon and into the evening. The sheer number of calls meant that by late Monday, many people were still waiting for the SES to visit their homes, where hailstones had penetrated roofs and caused flooding.