According to the old Icelandic calendar the year is divided into two equally long seasons, 6 months of winter and 6 months of summer. Each month is 30 days long and to account for the extra days of the year, a period of summer bonus (sumarauki) is added in the middle of summer between the months sólmánuður and heyannir. This period is four days in normal years and eleven days in leap years. Each month starts on the same weekday every year. Although we use the Gregorian calendar now, there are remnants of the old calendar still in our culture. Like the first day of winter. It is the first day of the first winter month, gormánuður, the Saturday between 21. and 28. October.
Summer in Iceland is not 6 months long and winter lasts for much more than 6 months. Therefore the first frost has arrived long before the first day of winter and winter is still running the show on the first day of summer. About 10 years ago the first frost date here in SW-Iceland was invariably in September, often very early in September. My daughter's birthday is one of the last days of September and there were hardly ever unfrozen flowers left in the garden on her birthday. This has changed in the past few years. There have been a few Septembers in a row that have not seen a single frost night. The first frost has moved well into October. This year it was October 22nd, four days before the first day of winter, which is on Saturday.
From a gardening perspective this is an excellent development. Plants that flower very late in the season have a better chance of flowering, maybe even plants that didn't stand a chance a decade ago. However, from a global standpoint, the reason for the delayed frost is nothing to rejoice over. It's the same reason that is causing our glaciers to disappear. The reason that is causing more extremes in the weather all over the globe in the forms of wildfires, floods, droughts and storms of, up until now, unknown magnitude. And although the short-term payoff here in the North is a longer growing season, which is very difficult to frown at, the fact remains that the climate crisis is a real and ever present threat to our existence.