Q 01/05

When it is winter in the Northern Hemisphere, what season is it in the Southern Hemisphere?

A) Summer

B) Autumn

C) Spring

D) Also winter

Answer · why

A) Summer

Australians and South Africans eat Christmas dinner in midsummer, and their meteorological winter runs June to August.

Q 02/05

Meteorologists in the Northern Hemisphere count winter as which three months?

A) November, December and January

B) December, January and February

C) January, February and March

D) December, January, February and March

Answer · why

B) December, January and February

Astronomers start it later, at the December solstice, and run it to the March equinox.

Q 03/05

What causes the seasons, including winter?

A) Earth's changing distance from the Sun

B) Sunspot cycles

C) The tilt of Earth's axis

D) The Moon's gravitational pull

Answer · why

C) The tilt of Earth's axis

The axis leans 23.44 degrees from the plane of the orbit, so each hemisphere takes turns pointing away from the Sun.

Q 04/05

Earth is actually closest to the Sun (perihelion) during which month?

A) July

B) March

C) October

D) January

Answer · why

D) January

It happens about two weeks after the December solstice, in the depths of the northern winter, which is why distance is not what makes winter cold.

Q 05/05

On which dates does the shortest day of the year in the Northern Hemisphere fall?

A) 21 or 22 December

B) 24 or 25 December

C) 1 or 2 December

D) 30 or 31 December

Answer · why

A) 21 or 22 December

The Sun is at its lowest arc in the sky; Newgrange in Ireland is aligned to its sunrise and Stonehenge to its sunset.