He went to Degerfors Elementary School but upon the death of his father, his mother moved the family to Sundsvall, where Sandström worked in a sawmill while being tutored.

Thanks to local benefactors, he entered a Stockholm technical school, and although he never received an official diploma, he excelled in mathematics and frequented scientific circles.

The Professor of Mathematical Physics in Stockholm was working on weather forecasting and the theory of the generalized hydrodynamic circulation in the late 1890s.

In a series of publications, Sandström analyzes the general atmospheric circulation and develops graphic predictive techniques that make him known.

When Bjerknes' grant ended, he was hired by Otto Pettersson as his main assistant at the Swedish Hydrographic and Biological Commission.

Sandström also receives an offer from Fridtjof Nansen in Bergen to help with the book "Lehrbuch der Cos-Physen Physik" by Svante Arrhenius (1903), to write the part on air masses and dynamic meteorology.

In 1908, Sandström was hired as technical manager of the new Hydrographic Agency in Stockholm, despite the lack of a diploma, with the help of Bjerknes' recommendation and his own publications.

In addition to expeditions and a number of personal boat trips in the Arctic, Sandström traveled several times in winter to Bergen to meet with Professor Bjerknes to discuss the theory of the weather fronts and air masses.