A lack of winter would indicate that the world's axis had shifted substantially, and its orbit had also changed. Winter is caused by the Earth's axial tilt, which, at certain points throughout the year, leads areas of the world to be further from the sun at different times in the year, hence why Australia has winter in July/August time, and in Britain it is winter in December and January. The Earth would also probably be flat and perpendicular to the sun so that everywhere receives exactly the same amount of solar rays (though to clarify, I am aware that this is impossible).
It would probably violently damage our ecosystems by forcing creatures that adapted to surviving winter to change ancient behavioral patterns, and giving plants and animals better adapted to warm conditions the opportunity to take over previously chilly climates, potentially destroying thousands of species. In the unlikely event that this did not occur, less biodiversity would still come about because everywhere would have a similar climate, so all the same animals and plants would thrive in most places.
On top of this, if all the seasons were similar, we would only understand the concept of spring, summer and autumn, which means that the smaller changes in temperature and climate between these seasons would seem greater to us, and we would probably 'invent' a new winter for the coldest part of the new year.
This answer takes into account only what would happen if winter as I know it disappeared from my country, and most (usually) inextreme climates. I have not addressed the question of whether the Arctic's "perpetual winter" ending would destroy many parts of the world by raising the sea levels several meters.
the earth would explode
It is - every winter (in the north).
Because it tell you that it is gonna be cold and winter is coming
Winter is a time period but it would depend where you lived as to what months in the year it would be.
It depends on where you live. In the south tornadoes usually occur in late winter, spring and summer. In the north tornadoes usually happen during the late spring and summer. Overall tornadoes can happen at any time of year.
the earth would explode
It would shrink. (>'-')>
It would develop a bizarre accent.
They would freeze to death
If a naked person tried climbing Mount Everest in Winter he would probably die from the cold very quickly.
Persephone would have to spend a portion of the years time in the Underworld (Winter).
The amount of hours that happen at night during the Winter can vary greatly by location on Earth. For instance, near the North Pole, it can be dark the entire winter.
Demon's Winter happened in 1988.
Winter of Terror happened in 1951.
Winter Challenge happened in 1991.
Cold Winter happened in 2005.
Winter Gold happened in 1996.