Thunderstorm Outlook
Issued at 8:05am 21/06/2026
Valid from 8:05am 21/06/2026 to Midnight 21/06/2026
Updated at 8am Sunday - a moderate risk of thunderstorms added to Wellington, Kapiti and the Wairarapa. A front moving through Grey and Buller this morning and early afternoon, brings showers, and a low risk of thunderstorms. For central parts of the country a combination of cold air in the upper atmosphere and a front with a southerly change, brings a moderate risk of thunderstorms about Wellington, Wairarapa and the Kapiti Coast during the afternoon and early evening. These thunderstorms may bring rain intensities of 10 to 20mm per hour, with the possibility of hail 5 to 15 mm in diameter. In addition, a low risk of thunderstorms and small hail extends from Horowhenua into south Taranaki, Nelson and the Marlborough Sounds as indicated on the chart. A low risk of thunderstorms also affects coastal Hawke's Bay in the evening. There is a minimal risk of thunderstorms or significant convection over the remainder of New Zealand during this period.
Issued at 7:16pm 21/06/2026
Valid from Midnight 21/06/2026 to Midday 22/06/2026
There is minimal risk of thunderstorms or significant convection during this period.
Issued at 9:02am 21/06/2026
Valid from Midday 22/06/2026 to Midnight 22/06/2026
There is minimal risk of thunderstorms or significant convection during this period.
Severe Thunderstorm Criteria
In New Zealand, MetService classifies a thunderstorm as severe if one or more of the following criteria are met:
Heavy rain (from thunderstorms):
Rainfall of 25mm/h, or more.
Large hail:
Hailstones 20mm in diameter, or larger.
Strong wind gusts (from thunderstorms):
Gusts of 110km/h (60 knots) or stronger.
Damaging tornadoes:
Fujita F1 - i.e. wind speeds greater than 116km/h (63 knots) or stronger.
Note: some tornadic systems such as funnel clouds, waterspouts and small land-based tornadoes are possible with thunderstorms that may not be classified as severe.
