The 2016 hurricane season just shifted from sleepy to fierce.

Tropical Storm Hermine strengthened into a hurricane on Thursday, just in time to strike the coast of Florida — the first hurricane to hit that state in nearly 11 years.

As that storm moves up the Atlantic coast, two other storms had been threatening Hawaii, a state that rarely receives such visitors. And there are probably more to come before the season concludes at the end of November.

This is, in other words, the height of the season, that time of year when conditions are the most favorable for making cyclones — and for making coastal residents nervous. It is also the moment that puts on display much of what we know, and still do not know, about hurricanes, and what to expect as climate change progresses.

Much of this, so far, is normal. This season is shaping up within the forecasts from the National Oceanic and Atmospheric Administration, which predicted in May that, in the Atlantic, there was a 70 percent likelihood of as many as 16 named storms.