Spinning in the surf near any river mouths should produce some Kahawai, especially if a big school comes in. Also if you have a license you can spin for Salmon at places like the Waimak. Most types of spinners should work, heavier ones will be easier to cast a distance.
Most of these spinners here will work for both Kahawai, and Salmon. https://fishingmag.co.nz/salmon-spinners-various.htm
And yes, there are fish around to be caught at this time of the year.