ClimateWatch: JULY outlook, El Niño & what it means for NZ & Oz

El Niño is officially here and still getting stronger in the months ahead, but it's harder to notice its effects in New Zealand and Australia at this time of the year. The concern will be going into spring and summer, as El Niño has historically increased the chances of some regions having much lower rainfall, and it can also add more oomph to the heat in the hotter months, and that can lead to bushfires and drought. But our part of the world is a distance from where El Niño is measured, and we have other climate drivers that affect our weather (like what happens over the Indian Ocean, Southern Ocean and Tasman Sea). We're seeing thresholds rising above where El Niño is being measured - we talk about how it is measured and why sea surface temperatures (SSTs) play a role - and how warmer than usual SSTs over the Tasman Sea may be a positive if you need rain. High pressure zones have been tracking further southwards right around the Southern Hemisphere lately - and this is driving in more easterlies for NZ and Australia (hence the eastern cloud and wet weather over recent weeks and months). Again, this isn't typical of how El Niño affects our weather - but winter weather is more likely to buck the trend, so the concern with El Niño is more about what happens once we get into spring and head towards summer. We look at general July air pressure, and rainfall - and while things may change over the coming weeks, we are seeing some "variety" at the moment - and if you need rain then variety is definitely a good thing.