50 Fun Facts About Weather

Almost all of Earth's weather happens in which layer of the atmosphere?

The troposphere is the lowest layer; weather in the stratosphere exists but is poorly understood.

Contrary to the classic drawing, large falling raindrops are shaped most like what?

Small droplets are spherical; as they grow they flatten underneath, and very large ones look like parachutes.

Which town in Meghalaya, India, is reportedly the wettest place on Earth?

It averages about 11,872 mm of rain a year, though two Colombian towns dispute the title.

Cherrapunji holds the record for the most rain in one month. Roughly how much fell in July 1861?

That is over nine metres in a single month; the town also holds the 12-month record of 26,471 mm.

Which desert is the driest non-polar desert in the world?

Some of its weather stations have never recorded rain; it may have had no significant rainfall from 1570 to 1971.

Very light, sporadic rainfall is known by what name?

A shower is brief and moderate, a cloudburst brief and heavy, and a downpour prolonged and heavy.

What is the globally averaged annual precipitation over the whole Earth?

Over land alone the average is lower, about 715 mm, because the oceans get more rain.

The air around a lightning flash heats to roughly what temperature?

That is several times hotter than the surface of the Sun, which is why the air expands explosively into thunder.

After seeing lightning, divide the seconds before thunder by what to get the distance in kilometres?

Sound travels about 343 metres per second, so roughly three seconds per kilometre or five per mile.

Where on Earth does lightning occur most often?

The Catatumbo lightning over the Venezuelan lake produces about 250 bolts a day.

Roughly what share of people struck by lightning survive?

Survivors often suffer lasting damage to internal organs and the nervous system.

Which country has by far the most tornadoes in the world?

Most strike the central and southeastern US, colloquially known as Tornado Alley.

The widest tornado on record, about 2.6 miles across, struck which town in 2013?

A 2004 tornado in Hallam, Nebraska had held the record at up to 2.5 miles wide.

The record-long 1925 Tri-State Tornado crossed Missouri, Illinois and which other state?

It stayed on the ground continuously for a record distance on March 18, 1925.

What radar signature helps forecasters spot a tornado forming?

Pulse-Doppler radar reveals hook echoes and debris balls in the velocity and reflectivity data.

A tornado over water is called what?

Tornadoes travelling over water can turn white or even blue.

A hurricane in the Atlantic is called what when it forms in the northwestern Pacific?

In the Indian Ocean and South Pacific the same storms are simply called tropical cyclones.

In the Northern Hemisphere, a tropical cyclone's surface winds blow in which direction?

The Coriolis effect reverses the spin south of the equator, where cyclones rotate clockwise.

Tropical cyclones rarely form within how many degrees of the equator?

Too close to the equator the Coriolis force is too weak to set the storm spinning.

About how many named tropical cyclones form worldwide each year?

More than half of them develop hurricane-force winds of 75 mph or more.

A Category 5 hurricane has sustained winds of at least how many mph?

The scale was devised in 1971 by engineer Herbert Saffir and meteorologist Robert Simpson.

Atlantic hurricane name lists skip Q, U, X, Y and which other letter?

Six rotating lists of 21 names alternate male and female, and notorious storms have their names retired.

What happens to the name of an especially deadly or costly hurricane?

A replacement name is picked at the next meeting of the WMO Hurricane Committee.

The strongest wind gust ever recorded, 408 km/h, was measured where in 1996?

It came during Cyclone Olivia and beat a 1934 record of 372 km/h from Mount Washington, New Hampshire.

The Beaufort wind scale was devised in 1805 by an officer of which country's navy?

Francis Beaufort's 13 classes originally described the effect of wind on a frigate's sails, not speeds.

What is the highest force on the standard Beaufort scale?

Force 12 is "hurricane force"; the original scale ran from zero to 12.

The Spanish-derived name for a long, straight-line windstorm is what?

The word means "straight", in deliberate contrast to the "twisted" tornado.

A haboob is an intense storm made of what?

The Arabic term was first used for dust storms in Sudan and applied to North American storms in 1972.

Which Montana town holds the record for the biggest 24-hour temperature swing, 103 °F?

A Chinook wind lifted the temperature from −54 °F to 49 °F on January 15, 1972.

The Blackfoot people call the warm Chinook wind by what name?

The föhn wind warms as it descends the eastern side of the Rockies, melting snow rapidly.

The official highest air temperature ever recorded, 56.7 °C, was measured where in 1913?

Some experts doubt the 1913 reading; if it were decertified, 54.0 °C readings would share the record.

The lowest temperature ever directly measured on Earth was −89.2 °C at which station?

The then-Soviet Antarctic base set the record on 21 July 1983; satellites have since seen −92 °C on the ice.

Snow crystals form in which geometric shape?

Supercooled droplets freeze into six-sided crystals around a particle in the atmosphere.

The world record seasonal snowfall of 2,896 cm fell at a ski area on which mountain?

The Washington ski area took the record in 1998–99 from nearby Mount Rainier.

Guinness lists the world's largest snowflake, from 1887 Montana, at what diameter?

It fell outside present-day Miles City; ordinary flakes are aggregates of many smaller crystals.

Who began the micrography of thousands of snowflakes in 1885?

Bentley's photographs revealed the wide diversity of flakes within a classifiable set of patterns.

The heaviest hailstone on record, 1.02 kg, fell in which country in 1986?

The largest by diameter, 20 cm across, fell in Vivian, South Dakota in 2010.

A cross-section of a large hailstone shows a structure like which vegetable?

The alternating clear and opaque layers record the hailstone's path through the cloud.

What keeps a growing hailstone aloft inside a thunderstorm?

Updrafts can reach 110 mph; the stone falls once its weight overcomes them.

Who proposed the Latin cloud names cirrus, cumulus and stratus in 1802?

The English chemist's system caught on quickly; Lamarck's rival French scheme did not.

By definition, fog reduces visibility to less than what distance?

Mist impairs visibility less; the two are very low stratiform clouds with no Latin names.

The Grand Banks, often called one of the foggiest places on Earth, lie off which island?

The foggiest places are typically above cold ocean currents, and most sea fogs are advection fogs.

Light returns from a raindrop most intensely at about what angle, giving the rainbow its radius?

Because of that 42° turning point, a rainbow vanishes when the Sun climbs higher than 42° above the horizon.

In a double rainbow, how do the colours of the secondary bow compare with the primary?

The secondary bow comes from a double reflection inside the droplets and sits about 10° outside the primary.

Who is usually credited with inventing the barometer in 1643?

Torricelli, once Galileo's assistant, argued that air has weight and pushes a column of mercury up the tube.

The word "monsoon" ultimately comes from an Arabic word meaning what?

It reached English via Portuguese "monção" and early modern Dutch "monson".

The monsoon supplies roughly what share of India's annual rainfall?

June 1 is taken as the onset date, marked by the monsoon's arrival in the southern state of Kerala.

In the climate pattern ENSO, the warming phase is El Niño; what is the cooling phase called?

The name El Niño, "the boy", came from Peruvian sailors referring to the Christ child.

Japanese meteorologist Wasaburo Oishi detected the jet stream in the 1920s near which mountain?

He tracked pilot balloons; the polar jets typically blow around 110 mph at 30,000 feet.

When the dew point is below freezing, it takes the name of which icy deposit?

Below 0 °C the moisture is deposited directly as frost rather than condensing as dew.