Property prices in the nation's largest markets declined in May, according to a data preview from CoreLogic.

In the first 29 days of May, CoreLogic's five city aggregate index fell 1.1%, says Tim Lawless, head of research with CoreLogic

The final numbers will be released on Thursday 1 June. 

The falls were spearheaded by declines in the Sydney and Melbourne markets, but Lawless says that when seasonal factors are taken into account, the May result may not be as weak as the current results are indicating.  

The softening of property prices comes against a cautious backdrop, with rising mortgage rates, softer auction results, a rising volume of advertised stock, cautious housing market sentiment, and a slowing investment market. 

Read more about Australia's property prices:

Sydney property prices down: CoreLogic

Economics, not investors, driving house prices, says REIA

Top end of market faring well, but change is in the air