The London Weather Station

A season is a part of the year. In most parts of the world we say there are four seasons in a year: spring, summer, autumn and winter.

Seasons are stages in the Earth's travel around the sun

We have seasons because the part of the Earth which is near the Sun changes, as the Earth goes round the Sun. As you know the earth turns around itself once a day (this is why we have day and night) but it also goes round the sun. It takes the earth one year to go round the sun. The seasons are different steps in this journey.

Seasons are different in different parts of the world

For some months the northern half of the Earth is closer to the sun and it is summer on the northern half, and for some months the southern part of the earth is closer to the sun and it is summer on the southern part. Whenever there is summer in the northern half, also called the northern hemisphere, there is winter in the southern half.
Countries in the middle between the two hemispheres who are placed around the earth's equator (for example countries in South America and in Africa) have no big change of season - for them it is very hot all through the year. That may sound great, but constant heat is a real struggle for people who live in it!

Equinox and Solstice

Whenever one part of the earth is closer to the sun and it is summer for this part, the days are longer and the nights shorter, because even though the earth turns around itself at the same spead, the angle between sun and earth is different and the sun can be seen for a longer time from the earth. As the earth continues to go round the sun towards what we call autumn, the days get continually shorter. There are 2 days during the year when the day has as many hours as the night. That is called "equinox". "Equinox" is latin and means literally: The night is equal (to the day). The longest day and the shortest are called "solstices".

These special days are sometimes used to draw the line between the seasons.

NNNNNNDDDDNNNNNN START OF WINTER (ca. 21./22.12.)
Winter Solstice: The shortest day of the year.

NNNNNDDDDDDNNNNN WINTER
The days get longer and the nights get shorter.

NNNNDDDDDDDDNNNN START OF SPRING (ca. 20./21.03.)
Spring Equinox: The day is as long as the night.

NNNDDDDDDDDDDNNN SPRING
The days continue to get longer and the nights continue to get shorter.

NNDDDDDDDDDDDDNN START OF SUMMER (ca. 21.06.)
Summer Solstice: The longest day of the year.

NNNDDDDDDDDDDNNN SUMMER
The days get shorter and the nights get longer.

NNNNDDDDDDDDNNNN START OF AUTUMN (ca. 22./23.09.)
Autumn Equinox: The day is as long as the night.

NNNNNDDDDDDNNNNN AUTUMN
The days continue to get shorter and the nights continue to get longer.

NNNNNNDDDDNNNNNN START OF WINTER (ca. 21./22.12.)
Winter Solstice: The shortest day of the year.

And so on!

On this daylight map you can see where the sun is shining at the moment:

Other starting dates for seasons

These are the season according to astromy, which means according to the position of the earth and the sun. But people do not always think of astronmy when they thing of the seasons. That is why most countries set different dates for the beginning of the seasons which are also easier to remember. For example in the United Kingdom, spring begins on February 2, almost seven weeks before the spring equinox! Summer begins on May 1, autumn on August 1, and winter on November 1. The Irish calendar is similar, but Spring begins on February 1. In countries like France and Germany there are again different dates to mark the beginning of the seasons. But this doesn't mean that the seasons are different there - people just chose different dates because they are used to them.

Check up-to-date weather information for London