Canberra has four genuinely distinct seasons — much more so than coastal Australian cities — and they are part of the city's experience. Summer (December to February) is warm to hot, with January highs typically around 28°C and frequent dry sunny days; this is bushfire season and smoke haze can be a real consideration. Autumn (March to May) is the standout: cool nights, mild sunny days, and the city's enormous deciduous tree canopy turning gold and red.
Winter (June to August) is cold by Australian standards, with frosts most mornings and occasional snow on the Brindabella range backdrop. Daytime temperatures usually 10-13°C; clear blue skies are common. Spring (September to November) brings the Floriade tulip festival, deep-blue jacarandas and weather that is variable but mostly fine.
For visitors, autumn and spring are the strongest seasons. The big festivals (Floriade in spring, the Balloon Spectacular in March, Enlighten in March) all cluster outside the deep summer and winter.