What is winter?
A: Winter is the coldest season of the year in polar and temperate climates.
It occurs after autumn and before what?
A: Spring.
The tilt of Earth's axis causes what?
A: Seasons; winter occurs when a hemisphere is oriented away from the Sun.
Different cultures define different dates as the start
of what?
A: Winter, and some use a definition based on weather.
When it is winter in the Northern Hemisphere, where is
it summer?
A: In the Southern Hemisphere, and vice versa.
In many regions, winter brings what?
A: Snow and freezing temperatures.
The moment of winter solstice is when the Sun's
elevation with respect to the North or South Pole is at what?
A: Its most negative value; that is, the Sun is at its farthest below the
horizon as measured from the pole.
The day on which this occurs has what?
A: The shortest day and the longest night, with day length increasing and
night length decreasing as the season progresses after the solstice.
The earliest sunset and latest sunrise dates outside
the polar regions differ from the date of the winter solstice and depend on
what?
A: Latitude.
They differ due to the variation in the solar day
throughout the year caused by what?
A: The Earth's elliptical orbit.
The tilt of the Earth's axis relative to its orbital
plane plays a large role in what?
A: The formation of weather.
The Earth is tilted at an angle of 23.44° to the plane
of its orbit, causing different latitudes to what?
A: To directly face the Sun as the Earth moves through its orbit.
This variation brings about what?
A: Seasons.
When it is winter in the Northern Hemisphere, the
Southern Hemisphere faces the Sun more directly and thus experiences what?
A: Warmer temperatures than the Northern Hemisphere.
Conversely, winter in the Southern Hemisphere occurs
when the Northern Hemisphere is tilted how?
A: More toward the Sun.
From the perspective of an observer on the Earth, the
winter Sun has a lower what?
A: Maximum altitude in the sky than the summer Sun.
During winter in either hemisphere, the lower altitude
of the Sun causes what?
A: The sunlight to hit the Earth at an oblique angle.
Thus, a lower amount of what strikes the Earth per unit
of surface area?
A: solar radiation.
The light must travel a longer distance through the
atmosphere, allowing the atmosphere to do what?
A: To dissipate more heat.
Compared with these effects, the effect of the changes
in the distance of the Earth from the Sun (due to the Earth's elliptical
orbit) is what?
A: Negligible.
The manifestation of the meteorological winter
(freezing temperatures) in the northerly snow–prone latitudes is highly
variable depending on what?
A: Elevation, position versus marine winds and the amount of precipitation.
Winter is often defined by meteorologists to be what?
A: The three calendar months with the lowest average temperatures.
This corresponds to the months of what?
A: December, January and February in the Northern Hemisphere, and June, July
and August in the Southern Hemisphere.
The coldest average temperatures of the season are
typically experienced in what months?
A: January or February in the Northern Hemisphere and in June, July or
August in the Southern Hemisphere.
