Hearing thunder
Thunder is the sound lightning makes, and counting the seconds after a flash tells you how far away it struck: about five seconds for every mile. That habit of measuring instead of guessing is useful far beyond storms.
What it may mean
Children learn a trick that turns fear into arithmetic: when lightning flashes, count until the thunder arrives, and every five seconds means about a mile. A storm you can measure feels less like a monster and more like weather. The rumble you heard now has a distance, a direction and, if you keep counting, a speed. That habit carries well beyond storms. Plenty of worries stay frightening because they are vague: a rumor of layoffs, a strange noise from the car, a hard talk you know is coming. Putting a number on them, even a rough one, often shrinks them. When thunder rolls, try the trick on your own week: which distant rumble could you measure instead of dreading? An English writer of 1556 even sorted thunder by the hour of the day: morning for wind, noon for rain, dusk for a tempest.
Depending on how you saw it
The first thunder of spring
Among the Zuni, the 1903 collection says, thunder first heard in the east was a sign the bear had stretched out his right arm and come forth, and winter was over. A first spring storm can feel like a turning point. What change of season, outside or inside you, has this year's first thunder announced?
Thunder in winter
Thunder during a snowstorm is rare enough to make people stop and listen, and an old English rhyme said winter's thunder never boded an Englishman good. Out-of-place sounds get more attention than familiar ones. Which unusual signal in your week deserves a second listen because it does not fit?
A rumble while you are outside
When thunder roars, weather services advise going indoors, because lightning can strike miles ahead of the rain. The sound itself is the warning. Which warning have you heard clearly and still not acted on?
Why it happens in nature
Thunder is the sound of air expanding explosively as a lightning bolt heats it almost instantly. Light reaches you almost at once, while sound covers about a mile every five seconds, so counting from flash to rumble gives the distance. Thunder can rarely be heard more than about ten miles away, and lightning can strike that far from the storm.
What folk beliefs say
England
Leonard Digges, quoted by Brand from his Prognostication of 1556, wrote that thunder in the morning signified wind, about noon rain, and in the evening great tempest; others, he noted, gave each weekday's thunder its own meaning, from deaths to plenty of grain.
Source: John Brand; Henry Ellis (ed.), Observations on the Popular Antiquities of Great Britain, vol. 3 (1849), vol. 3, p. 245. View the page
Zuni (New Mexico)
If the first thunder of the year sounded in the east, the Zuni said, the bear had stretched out his right arm and come forth, and winter was over.
Source: Cora Linn Daniels; C. M. Stevans (eds.), Encyclopaedia of Superstitions, Folklore, and the Occult Sciences of the World, vol. 2 (1903), vol. 2, p. 1021. View the page
England
An English rhyme ran: "Winter's thunder and summer's flood never boded Englishman good."
Source: Cora Linn Daniels; C. M. Stevans (eds.), Encyclopaedia of Superstitions, Folklore, and the Occult Sciences of the World, vol. 2 (1903), vol. 2, p. 1019. View the page
To reflect on
Which vague worry would shrink if you put a rough number on it?