Although Canberra's streets continue to be emblazoned with autumn colours, it could begin feeling a lot more like winter later this week.
Tuesday is forecast to reach 20 degrees with sunny conditions, but there is a chance of morning fog.
By Thursday, the forecast temperature is 13 degrees dropping to 11 degrees on Friday and with a cool weekend ahead.
Bureau of Meteorology engagement officer Morgan Pumpa said Canberra was forecast to experience settled weather conditions in the first half of the week, with the chance of some light rain in the second half.
"We do have single digits on the forecast for Canberra overnight and even getting as low as one degree on Friday morning, so overnight Thursday," Ms Pumpa said.
"This cold front and trough moving over in the second half in the week is really the first significant cold snap.
"It will start to feel a bit like winter with both the drop in overnight and daytime temperatures."
Ms Pumpa said temperatures in Canberra were a couple of degrees above the May average, which was between three and 15 degrees.
"The second half of the week will see a cold front and a trough move over the [ACT] and the south eastern parts of NSW," she said.
While autumn weather is fast giving way to winter conditions, bright and colourful autumn leaves are still in fine display across the capital for Canberra's Tree Week.
Canberra has also been declared an international tree city of the world, joining 138 cities recognised around the world for their leadership in managing urban trees.
City Services Minister Chris Steel welcomed the recognition, and said the capital's trees were one of the things that gave the city its special character.
Recognition as an international tree city requires local authorities to take responsibility for tree management, have a set of rules for managing the urban forest, along with an inventory of plantings.
Tree cities must also have a dedicated budget for tree management and plantings, and an annual celebration of trees.
Recognised cities, which are spread across 21 countries, include Toronto, Canada; Auckland and Wellington, New Zealand; Stockholm, Sweden; and Sheffield, England.
The program is an initiative of Abor Day Foundation and the Food and Agriculture Organization of the United Nations.
Tree Week began on Saturday, when the recognition as an international tree city was announced.
Tree week events include a heritage tour of the Yarralumla Nursery, where many of Canberra's urban trees were propagated, along with poetry readings, tree walks and events at ACT libraries.
Meanwhile, the ACT government is considering new laws that would mean home owners need to plant two new trees for every tree they remove, or pay $600 a tree if planting two trees is impossible.
Property developers would be required to replant trees they removed or make a payment based of the lost tree's value.
