Someone once said that, if it wasn't for weather, eighty percent of people couldn't start a conversation. Sometime, people ask if you think it is going to rain. At other times, they ask if it is hot enough for you. Whether the question asks you to forecast or make a qualitative assessment, the interest in weather is evident in the question. Everyone knows some examples of weather lore, sayings that attempt to explain or forecast the weather. There are scores of these sayings like "Count the stars within a halo around the moon and that is the number of days till it rains."
Climate lore exists too but it is not in the form of sayings. This lore is evident in names given to hot spells and cold spells. There are several of these names in widespread use in Kentucky. Each has some basis in fact. The graph below shows the average daily temperature for a thirty year period in Bowling Green. Some of the perturbations in the plotted curve roughly fit the definitions provided by the climate lore. You may be able to imagine them from the plot.
Dog Days of summer gets its name from the rising of the Sirius (the dog star). In climate lore, it identifies a mid summer (in Kentucky, late July-early August) hot spell sustained over several days. This lore recognizes that a maritime tropical air mass can become a temporary resident and cause a flattening of the temperature curve. It produces forecasts that include "continued hot, humid, hazy, with scattered isolated afternoon thunderstorms."
Indian Summer is a warm spell that occurs is late fall (in Kentucky, usually late November) after freezing temperatures have become common. It recognizes the temporary return of a maritime tropical air mass before winter arrives.
January Thaw is a warm spell that occurs in mid winter (in Kentucky, usually late January) that produces a period when minimum temperature remains above freezing for a few consecutive days. It recognizes the incursion of a maritime tropical air mass that displaces winter for a short period. It is welcomed now but may not have been before the time of paved roads.
Dogwood Winter is a cold spell that occurs after spring seems to have arrived (in Kentucky, usually mid April) and while the dogwood trees are in bloom. In the northern parts of Kentucky or where dogwoods are uncommon, it may be called locust winter for the tree that blooms at about the same time. The climate lore name recognizes the return of a continental polar air mass of sufficient severity to feel like winter again.
Blackberry Winter is a cold spell that occurs while blackberries are in bloom (early May in Kentucky). This folklore recognizes another, but less severe, return of a continental polar air mass after maritime tropical air masses have begun to dominate.
Linsey-Woolsey Britches Winter refers to the last surge of cold continental polar air in the spring (usually in late May in Kentucky). It relates to the last time during spring that winter clothing of homespun linen-wool combination had to be worn.
Similar folklore seasons are recognized in Europe and elsewhere. These folklore seasons are a combination of fact and myth. They are factual in that such hot and cold spells occur during year. They are mythical if applied to a specific time each year. There are no quantitative measurements that would allow unquestionable identification of them. Nevertheless, it is remarkable that these hot and cold spells would have been noticed before extensive climate records were available and before climatological statistics could be used.