People just died. Seriously, a lot of people just died. Entire cultures would be wiped out, and if they never made anything out of a material more durable than wood then we might never find any record of their existence.

The benefit of being able to predict weather events like we can today really can’t be overstated. In the past, storms would appear with no warning and there would never be time to prepare.

In the present we can build permanent structures like storm shelters, wrap items in plastic to keep them useful even after being fully submerged in water, and we have an incredible capacity for mobility so it’s actually possible to get away from a disaster before it strikes. Compared to previous centuries, what we can do now is practically magic.

I highly recommend Fall of Civilizations. There are a lot of cultures that were wiped out, sometimes by natural disasters, sometimes through gradual degradation, and in many cases for reasons that we don’t fully understand because any records are long rotted away.