July 2019 was characterised by higher than normal mean sea level pressure east of New Zealand. Lower than normal pressure was observed in the Tasman Sea and extended over the South Island. This set up resulted in more westerly air flows than normal across the country.
It was New Zealand’s 2nd-warmest July on record. Temperatures were above average (0.51°C to 1.2°C above average) or well above average (>1.2°C above average) nearly everywhere across New Zealand, with the most unusually warm temperatures in the interior South Island and parts of Manawatu-Whanganui. Many locations observed record or near-record warm mean, mean maximum, and mean minimum July temperatures.
Rainfall was above (120% to 149% of normal) or well above normal (>149% of normal) for the majority of the South Island with the exception being a portion of eastern Southland and lower and interior Otago where below normal rainfall (50% to 79% of normal) was observed. For the North Island, above or well above normal rainfall was observed in central and southwestern areas while near normal (80% to 119% of normal) or below normal rainfall was observed in the majority of the north and east.
As of 31 July, soil moisture was near normal for most locations while a small area in lower coastal Canterbury and upper coastal Otago observed below normal soil moisture.
Percentage of normal rainfall for July 2019
End of month water balance in the pasture root zone for an average soil type where the available water capacity is taken to be 150 mm.
Departure from average air temperature for July 2019.