The weather's influence is all-pervasive. Not only does it affect our daily activities but governs the length of time available to us to carry them out. In a very small way, the weather influences the rate of Earth's rotation, and thus the length of the astronomical day. It all has to do with a principle called the conservation of angular momentum.
The concept of momentum was introduced in the late 17th . century by Sir Isaac Newton. It represents what might be called a "quantity of motion".
Angular momentum extends this idea to rotating bodies, representing in essence a "quantity of rotation". Angular momentum depends on the rate of spin of an object, and on the distance of its various parts from the axis of rotation. It is a cardinal principle of physics, from the atom to the cosmos, that angular momentum is "conserved' : it must remain constant in the absence of external stimuli.
As a first approximation, the Earth-atmosphere system can be regarded as free from external influence, and therefore its angular momentum must remain constant.
But the rate of movement of the atmosphere itself is not constant. Apart from day-to-day changes, its average speed increases significantly in the more vigorous regime of the northern winter, noticeable to us as an increase in wind strength, and shows a corresponding decrease in summer.
Now an increase in wind speed implies an increase in the angular momentum of the atmosphere about the Earth's axis of rotation. Therefore, if the angular momentum of the whole Earth-atmosphere system is to remain constant, there must be a compensatory change elsewhere: the Earth itself must lose momentum, and slow.
This slowing of the Earth is caused by changes in the friction, or drag, on its surface atmosphere, and by changes in the pressure from strong winds on large mountain ranges.
The end result is that when the average wind increases, the Earth slows. And when the Earth spins more slowly, we have a longer day. The effect is tiny but measurable. It turns out that the day, on average, is about one millionth of a second longer in winter than in summer.
A long spell of stormy weather may not just seem to be never-ending; in reality, it may be just a little longer than it should.