Sweden: Late Spring/Early Summer/Early Autumn, approximately May, June and September.
Temperatures between 15-25 Β°C, low humidity and lots of hours of daylight (18 hours in early June). Great conditions for biking and just all-round pleasant to be in.
Early Spring is too wet, Late Summer is too hot and humid, and Late Autumn is too wet and dark. Winter sucks, unless it's an unusually cold year and we get consistent snow coverage. Wet and extremely dark.