The mercury is forecast drop into single figures by Friday morning in Queensland's capital, as cold and very dry air migrates across the region from the southwest.

Morning temperatures will become progressively colder in the lead up to Friday, which will likely be the coldest of the year so far.

If the current forecast minimum of 7 degrees is holds true, it would be the coldest May morning since 2006, when a low of 5 degrees was observed.

Minimum temperatures are due to become milder during the first few days of June, as winds shift onshore.