Auckland city could expect a few more showers throughout the rest of the day, and with these heavy showers there was potential for more hailstorms, he said.
It was hard to say where hailstorms would hit.
"It is not unusual to see hail when you get these nice big showers and cold tops. It's the perfect condition for hail to form."
A cold snap was expected later this week, with rain, wind and snow set to hit most of the country.
"We are not quite over winter just yet."
A cold outbreak would arrive at the end of the week, and would send temperatures plummeting again with more snow in the south, Mr Law said.
Southland, Otago and Canterbury could all expect a dusting of snow later in the week, he said.
Meanwhile the east of the North Island was set for a wet week.
A severe weather warning had been issued for heavy rainfall for Gisborne and Hawkes Bay north of Napier.
Waikato and the Central Plateau as well as the South Island could expect frosty nights from this evening, he said.
"Once again, the temperatures are likely to see-saw across the country.
"After a frosty Monday night temperatures will recover slightly on Tuesday with a brief return to milder northwesterlies."
