To avoid sunburn, the most important thing you can do is get morning sunlight, especially at sunrise. This has a photobiomodulation effect that primes your skin for the rest of the day. It is also smart to build your solar callus to the months leading up to summer.

However, if you want to build up for next year instead to not be burned during peak UV index times (11AM-3PM) then this year try to maximize the amount of sun you get during the beginning of the day (around 7-10AM) and the end of the day (around 5-7PM) and do it consistently.

Also make sure you are grounding regularly, drinking lots of water, consuming antioxidant rich food (take astaxanthin as well), minimize your blue light diet (minimize screen time and use blue light blocking glasses and/or the @daylightco ) and swap out all your LED bulbs with incandescent bulbs. This is the way!