Spring Equinox Was Today

The length of day wasn't exactly 12 hours as you would expect on the equinoxes but 12 hours and 11 minutes on this particular latitude. The reason is that the density of the atmosphere changes as light passes through it and not perpendicular to the layers of different density (that the change in density is gradual does not change this). Light is slightly bent on its course through the atmosphere. This causes objects in the sky to appear to be at a higher angle than they actually are.

Roughly 1000 km further to the north in Ivalo, the length of day was 12 hours 14 minutes.

In Singapore, which is nearly on the equator, the length of day was 12 hours 7 minutes today.

Why the difference? As I wrote in the above, the angle at which the light penetrates the atmosphere is different on different latitudes.

At the north pole, the sun is right on the horizon from which it rises to about 23.4 degrees above the horizon at summer solstice, after which it slowly descends back to the horizon until it sets at winter solstice three months later.

In Southern Finland, March is a clearly winter month when it comes to the climate. During the last week of March, the average diurnal temperature begins to stay above freezing, which causes the onset of spring thaw.


Piles of dirty snow everywhere. In a couple of weeks, it is likely that they will be gone.


When the snow is gone, the grit remaining on the walkways and the roads has to be removed. If it does not rain, there will be a lot of dust in the air making life difficult for some people. After that, the pollen season begins and it lasts until the end of August for the most parts. The last plants to release pollen do so until the first overnight frost, which usually occurs in late September.