I already had two older models of these fairy lights and am satisfied so far with them. They are actually far as weatherproof. My other two chains have now three months behind with winter ice, snow and rain. One has survived well and is still lit perfectly, the second broke down sometime after three months of ice and snow. Therefore, I will replace it with this.
The chains invite also in cloudy weather well and keep min 3-4 hours. With sunshine and blue skies keep the following night to participate, 4 clock by morning. That's what happens with solar, it can only be lit as long as the sunshine on the day was before.
The chain will turn on by themselves when it is dark enough. Whether they would be switched off, I can not say, because normally the energy is used up before it's light again.
The solar panel is easy to unscrew and operated with a normal AA battery, should therefore go wrong, you can easily replace it. In principle, I could probably fix the small board my old chain, if I knew what exactly the problem is. Maybe it was not on the board, because the actually looks still fine out, perhaps the chain has gotten itself a little frost damage, because she jumped a few days before she was finally dead. A rodent damage, a curious magpie blackbird or can of course have anything nibbled and have so damaged the circuit, which is difficult to say.
But as chain 2 still does perfectly, I assume that the rather rare, but I would say in terms of weather resistance, rain is OK, but he probably should not freeze on the chain, because some damage might yet take. When mounted somewhat protected and not completely snow and ice is delivered, ie, for. Ex. On the balcony, there should be no problems, not even with rodents, playful cats or neighbor cheeky magpies.