This night there began, and continued until the 18th, a certain fine rain, which froze whilst it fell, and made icicles upon the trees. There was such a quantity of it, that the weight bowed the trees down to the ground and broke the branches. Note, by the way, that this was on the hills. For about half a mile near the river it did no injury. It began at Fiesole, and extended to the Mugello; and at San Godenzo and Dicomano it did much harm. On my land at Dicomano it tore from the roots several chestnut-trees and oak-trees, and broke nearly all the branches of the olive-trees and every other kind of wood, so that at one of my farms the branches alone made twenty piles of wood; and some of the broken limbs of the chestnuts were more than two feet thick, such as was never seen before. Those who chanced to be in the woods, thought that the world was coming to an end, when they heard everything cracking, and the deafening noise overhead. There was such a heap of grass that it weighed several pounds; and the stubble of the corn in the fields looked like organ-pipes. The stacks appeared to be roofed with glass, and it was too dangerous for anyone to walk in the country. The farms were ruined for many years, the fruit-trees not bearing fruit, the olives remaining like suckers, and the oak-trees being all spoilt. It was incredible, but true.
The Arno rose very high, and ruined the mill of the Ponte a Rubiconte, next to Santa Maria delle Grazie, and a porter was drowned there. The mill was a spinning-mill. The river overflowed its banks in several places.
The Day of San Bastiano (St. Sebastian); there was the severest snowstorm in Florence that the oldest people living could remember. And amongst other extraordinary things, it was accompanied by such a violent wind that for the whole day it was impossible to open the shops, or the doors and windows. It last from the Ave Maria one morning to the Ave Maria the next morning, twenty-four hours, without ceasing for a minute, and without the wind abating, so that there was not the slightest crack or a hole, however small, that did not let a heap of snow into the house. In fact there was not a house so hermetically sealed as not to become so full of snow that it took several days to clear it out. All along the streets one saw heaps of snow, so that in many places neither men nor beasts could pass. There was such a quantity that it took a long time to melt away, as sometimes when boys make a snow-lion. In fact, these mountains lasted a week. It is difficult to believe without having seen it. And the same thing happened in my villa at Dicomano. I sent Benedetto to clear the house, and he found as much snow inside as if it had been roofless; and this was after a week. So it was everywhere alike.
A landslide occurred in the Alps near Bellinzona which is described by Leandro Alberti in 1550:
In the past years an earthquake caused a large part of a mountain to collapse, in such a way that the Bregno valley came to be obstructed; and as the river came to be dammed up, it produced a large and dark lake with great damage to the inhabitants of the valley, many of whom were drowned and their houses submerged. And so it stayed for quite some time, until the fallen earth made gradually soft by the infiltrations of the water and being no longer sufficiently strong to retain the immense pressure of it, suddenly burst open to the fury of the swollen waters. And since the former river bed, which was joined to the Ticino, was no longer adequate to contain it, the water flooded all the neighbouring regions, overthrowing in part even that strong wall which Lodovico Sforza had built near Bellinzona.
... for in our own times a similar thing has been seen, that is, a mountain falling seven miles across a valley and closing it up and turning it into a lake.