You should wear sunscreen whenever the UV Index is three or above. You can check what time you should be wearing protection based on your region by using the Sun Protection Alert map on the Sunsmart NZ website. The UV Index can also be high throughout winter and especially if you’re around reflective surfaces, so if you’re a keen surfer or snowboarder, you need to be extra careful.
It’s a common misconception that the heat from the sun causes sunburn, and that this causes cancer, because you can often feel the heat from the sun and you can’t feel or see UV. But even on a cloudy day, UV radiation can harm your skin.
Check the UV index on the NIWA website, or download the free SunSmart app that not only shows you the index, but also indicates the times during the day you’ll need to be wearing protection. But really, it’s a good idea to get into the habit of applying sunscreen every day.