Thanks! It happens very rarely and only during spring and autumn, some 6-8 days per year in total. You need to be VERY persistent to capture it, getting up around 4AM every day for weeks just to check on the weather conditions. By 5AM you gotta be on top of a really tall skyscraper (which itself is not easy) and be ready to shoot. By 9AM the latest everything is over.
You need to be really persistent, because this fog only happens very rarely during spring and autumn for some 6-8 days per year in total. To capture it you need to get up at around 4AM every day during the season just to check weather conditions and if it looks like it is going to be foggy you gotta be on top of a skyscraper (which itself is not easy) before sunrise. By 9AM the latest it's all over.