It is not just the water level or the size and density of the ice jam that are significant.

What matters is what triggers the floods, and this time, unlike traditional spring freshets, they are not caused by melting alone, but also by frost – a highly variable temperature regime not previously seen in Latvian winters, combined with high levels of precipitation. In the Daugava basin, stable frost prevailed from mid-November to mid-December; rivers froze over and a thick blanket of snow formed, which melted almost completely just before Christmas. This was followed by more frost, increasing the volume of ice in the Daugava, but the flood cycle was set in motion by the unprecedentedly intense thaw at the turn of the year, when it rained for several days and air temperatures reached as high as +10 °C.

Ice movement and the formation of jams began. This has happened in other years when ice moves during winter, but usually, it is halted by the return of stable frost, water inflow into the river decreases, ice jams freeze solid, they stop compacting, and the water finds its way to flow underneath or through gaps. This time, the frost is too weak; instead of freezing the river solid and calming the waters, it only creates new frazil ice and ice chunks that continued to compact. First near Pļaviņas and Zeļķi, then the ice dam grew longer and longer, reaching Jēkabpils.