No, you can activate them anytime but some events such as the mayors office is accesible at night. and yeah the weather is supposed to be amped up in everyway oh and heres a tip: look everywhere at night there is a hidden place that appears, when you buy a bucket and the seed of life, Remember that there is a fire by your house to melt snow ;) andddd Anamnesis 1 is the only place to grow flowers.