An excellent report was prepared by NIWA scientists for the MDC Councillors and staff. It was presented to the Environment Committee by Gregor Macara on April 22nd, 2021 and updated them on the latest information on climate change projections and impacts for the Marlborough region. It's well worth looking at just to see the the Executive Summary. Drought potential is projected to increase across Marlborough, with annual accumulated Potential Evapotranspiration Deficit (PED) totals increasing with time and Climate change projections and impacts for Marlborough 9increasing greenhouse gas concentrations. By 2040, PED totals are projected to increase by 50-150 mm. By 2090, PED totals are projected to increase by 50-200 mm (medium concentration pathway) or 75-250 mm (high concentration pathway). Another significant projection is that mean annual low flow (MALF) magnitudes are expected to decrease across both
greenhouse gas concentration pathways and future time periods for most catchments. A decrease in MALF is expected to exceed 50% for most of the river systems in the region with increased greenhouse gas concentration and time.
The full pdf file can be downloaded here -
An earlier report titled "Blenheim climate 2019, trends and possible climate change effects" prepared by Rob Agnew was presented to the Environment Committee of the MDC on March 12th , 2020.
Weather data for the Blenheim weather station at the Marlborough Research Centre’s Grovetown Park campus is freely available at: http://www.mrc.org.nz/weather