Quiz of the Day
St. Swithin's Day & Weather Folklore
Wednesday, 15 July 2026
Rain on St. Swithin's Day means 40 more days of rain — but does folklore hold up to science?
1. According to St. Swithin's Day folklore, if it rains on July 15th, what is supposed to follow?
- A mild winter
- A month of drought
- 40 days of rain
- 40 days of sunshine
St. Swithin was a 9th-century Bishop of Winchester whose dying wish was to be buried outside so rain could fall on his grave. When his remains were moved indoors in 971 AD, legend says it rained for 40 days in protest. Meteorologists have tested the prediction repeatedly and found no reliable correlation.
2. Which of these weather sayings has some scientific basis?
- Red sky at night, sailor's delight
- Animals predict earthquakes
- Counting cricket chirps gives temperature
- Moss on north side means wet weather
'Red sky at night, sailor's delight; red sky in morning, sailor's warning' has real meteorological basis. In temperate latitudes, weather systems generally move west to east. A red evening sky means dust particles (dry air) are in the west — suggesting fair weather approaching. A red morning sky means dry air has passed, and moisture is incoming.
3. The study of how plants and animals behave in relation to seasons and climate is called what?
- Phenology
- Climatology
- Ecometeorology
- Ethology
Phenology tracks things like the first day plants flower, birds migrate, or insects emerge each year. Long-term phenological records — some going back centuries — are now some of the most powerful evidence for climate change, showing that spring events are arriving earlier and earlier across much of the world.
4. What does a barometer measure?
- Atmospheric pressure
- Wind speed
- Humidity
- Temperature
Evangelista Torricelli invented the barometer in 1643 while trying to explain why water pumps couldn't raise water more than about 10 metres. He realised the atmosphere has weight that pushes down on liquids. Falling pressure typically signals approaching storms; rising pressure indicates clearing weather.
5. The Beaufort Scale measures what meteorological phenomenon?
- Storm size
- Rainfall intensity
- Wind force
- Lightning frequency
Invented by Irish hydrographer Francis Beaufort in 1805, the scale ranges from 0 (calm) to 12 (hurricane). It was originally based on what a sailor could observe about sea conditions and sail settings. Scale 12 — a hurricane — corresponds to winds above 64 knots (119 km/h).
6. Which cloud type, found at very high altitude, is made entirely of ice crystals and signals approaching weather change?
- Cumulus
- Nimbostratus
- Cirrus
- Stratus
Cirrus clouds form above 6,000 metres where temperatures are well below freezing. Their wispy, hair-like appearance (cirrus means 'lock of hair' in Latin) is caused by ice crystals being blown by high-altitude winds. A thickening layer of cirrus often indicates a warm front approaching within 24-48 hours.
7. The 'Coriolis effect' explains why hurricanes spin in opposite directions in different hemispheres. Which direction do they spin in the Northern Hemisphere?
- Either — it's random
- Counter-clockwise
- Clockwise
- Depends on temperature
The Coriolis effect, caused by Earth's rotation, deflects moving air to the right in the Northern Hemisphere and to the left in the Southern Hemisphere. This means Northern Hemisphere hurricanes rotate counter-clockwise while Southern Hemisphere cyclones spin clockwise. The effect is too weak to influence toilet flushes — a persistent myth.
8. What is the name for the phenomenon where a warm layer of air traps a cooler layer below, creating hazardous air quality?
- Thermal cap
- Pressure lid
- Atmospheric inversion
- Convective suppression
Temperature inversions trap pollutants near the ground because the normal convective mixing that disperses them is prevented. The Great Smog of London in December 1952, caused by an inversion trapping coal smoke, killed an estimated 4,000-12,000 people and led directly to the Clean Air Act of 1956.
9. Which country experiences the most tornadoes per year in the world?
- Canada
- United States
- Australia
- Bangladesh
The US experiences about 1,200 tornadoes per year — more than any other country. The region called 'Tornado Alley' (Texas, Oklahoma, Kansas) is particularly prone because warm moist Gulf air collides with dry cold Arctic air above flat terrain, creating ideal conditions for severe supercell thunderstorms.
10. What is the technical term for a rainbow seen at night, formed by moonlight instead of sunlight?
- Moonbow
- Selenbow
- Noctibow
- Lunar arc
Moonbows are real but rare, requiring a bright full moon, clear sky, and rain or mist at the right angle. To human eyes they typically appear white because the light is too dim to trigger colour vision, but long-exposure photography reveals they're coloured exactly like solar rainbows. Victoria Falls in Zimbabwe is one of the world's best moonbow-viewing spots.
11. El Niño, a climate pattern that disrupts global weather, is defined by unusual warming of surface water in which ocean?
- Atlantic Ocean
- Arctic Ocean
- Pacific Ocean
- Indian Ocean
El Niño (Spanish for 'The Boy Child,' referring to the Christ child) was named by Peruvian fishermen who noticed the warm current arrived around Christmas. It disrupts fisheries, causes droughts in some regions and floods in others, and affects weather patterns across the entire globe.
12. What is the record highest air temperature ever officially recorded on Earth?
- 56.7°C (134.1°F) in Death Valley
- 58.0°C in Libya
- 54.4°C (129.9°F) in Death Valley
- 61.2°C in Kuwait
The record was set at Furnace Creek in Death Valley, California, on July 10, 1913. Death Valley regularly experiences the hottest surface temperatures on Earth thanks to its extreme below-sea-level elevation, basin geography, and sparse cloud cover. Summer temperatures above 50°C are common.
13. The Jet Stream, which strongly influences weather patterns in Europe and North America, flows in which direction?
- West to east
- North to south
- East to west
- South to north
Jet streams are fast-flowing air currents at high altitude that travel west to east in both hemispheres. They act as boundaries between cold and warm air masses and guide storm systems. When the jet stream buckles north or south (becoming 'wavy'), it can lock weather patterns in place for weeks, causing extreme heat or flooding.
14. Which instrument measures wind direction?
- Anemometer
- Hygrometer
- Barograph
- Wind vane
Wind vanes are among the oldest meteorological instruments, with examples dating to ancient Greece. Conventionally they point in the direction the wind is coming FROM — so a 'north wind' on a wind vane means the vane points north and the wind is blowing toward you from the north. Anemometers measure wind speed, not direction.
15. 'Petrichor' is the scientific name for which sensation associated with weather?
- The sound of distant thunder
- The pain of sudden temperature drops
- The smell of rain on dry earth
- The feeling of humidity before rain
Petrichor was coined by Australian scientists Isabel Joy Bear and R.G. Thomas in 1964 from the Greek 'petra' (stone) and 'ichor' (the fluid in the veins of gods). The smell comes primarily from geosmin, a compound produced by soil bacteria, and plant oils released from parched earth. Humans can smell geosmin in concentrations as low as 5 parts per trillion — more sensitive than sharks detecting blood.