Hawke’s Bay has a usually temperate climate – neither too cold, nor too wet, although we enjoy some hot days in summer.
However we are vulnerable to extreme weather conditions. Cyclone Bola in 1988 and a coastal storm in April 2011 caused a lot of damage and a long term cost to landowners. And although it seems unbelievable on a summer’s day at the beach, we get frosts and it can snow here and in the Winter of 2015 it did so as far down as the coast.
HBRC hosts regular climate talks when extreme seasonal conditions are anticipated or ongoing. These talks enable primary sector and agency representatives to learn about current conditions, water resource availability and forecasts for the coming seasons. Details from the talks will be in our NEWS page.
In general terms, on the East Coast, we see a relationship between our regional climate and the large circulation patterns in our hemisphere, particularly the ENSO (El Nino Southern Oscillation) between the east and west Pacific which determines El Nino and La Nina phases, and the IPO (Inter-Decadal Pacific Oscillation) which extends more broadly over the Pacific.
- ENSO - in the El Nino or negative phase we have cooler than normal winters and drier than normal summers in Hawke’s Bay, while during a La Nina or positive phase, conditions are warmer and wetter.
- IPO (inter-decadal Pacific Oscillation) – we generally associate higher annual average rainfall in Hawke’s Bay with negative phases rather than positive phases.
Climate records from the weather station in Napier’s Nelson Park since 1940 show small but significant changes over time. The number of hot days (temperatures over 25 deg C), the duration of warm spells and the day-night (diurnal) temperature range appear to have increased. There is a decreasing number of cold days (temperatures below 10 deg C).
Hawke’s Bay can be prone to localised or widespread drought – extended periods of below average rainfall. Significant droughts were 1995/96, 1997/98 and 2012/13.
Severe weather, especially cyclones from the tropics, can then bring significant rainfall resulting in landslips, high river and stream flows and localised flooding. Storms can also bring high seas, resulting in sea water inundation along the coast, property damage and erosion of beaches.
Intense rain storms over urban areas can leave stormwater systems unable to drain or pump water fast enough, resulting in surface flooding and damage to roads and properties.
It’s not uncommon for strong wind warnings to be issued for Hawke’s Bay, particularly across the exposed plains. Wind erosion of exposed paddocks, damage to trees, power lines and buildings and toppled vehicles can be the result.