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

Meteorological winter is December, January and February, the three coldest months on average; astronomical winter starts later, at the December solsti...

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

Perihelion falls in early January, around 3 January, about two weeks after the December solstice, which is why Earth-Sun distance is not what makes no...

Q 05/05

The winter solstice, the Northern Hemisphere's shortest day, when the Sun traces its lowest arc, falls on which dates?

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 winter solstice falls on 21 or 22 December, when the noon Sun is lowest in the Northern Hemisphere sky; the exact date shifts with the leap-year c...