MetService has issued a severe weather watch for the upper North Island, with heavy rain and winds expected to end the late-winter fine spell.
Auckland and Coromandel should expect bursts of rain on Wednesday and Thursday nights, and early on Friday morning.
Northland's turn comes from late Thursday morning through to Friday.
There is also the potential for gale-force winds in exposed parts of Northland, Auckland and Coromandel from Thursday afternoon.
"The several days of dry weather has actually put some northern regions just a tad drier than usual for late August - so this rain will actually be welcome, but may make things wetter than normal again," says weather forecast site weatherwatch.co.nz.
MetService says it's not yet a full-fledged weather warning, but conditions could escalate.
Further south, the West Coast looks likely to get some heavy rain in the next week-and-a-half, according to weatherwatch.co.nz.