When will storms hit the USA — checking the hour for your town

Severe weather season in the US is a wave that travels north. It does not sit still.

March to May — the Gulf Coast and the Deep South peak early, while northern states are still cold.

May to June — the classic Plains season. Oklahoma, Kansas, Nebraska and Texas hit maximum activity, producing the supercells the region is known for.

June to August — activity shifts to the Upper Midwest, the Great Lakes and the Ohio Valley. Summer also brings a separate pattern: daily afternoon storms along the Gulf Coast and through Florida, driven by heat and sea breeze rather than by a front.

November — a smaller secondary peak returns to the South, weaker than spring but real.

Florida records more lightning strikes than any other state; in summer storms there are close to a daily fixture rather than an event.

Most thunderstorms peak in the late afternoon and early evening, roughly 15:00–21:00 local time. The mechanism is the same everywhere: the sun heats the ground through the day, that heat feeds rising air, and the atmosphere releases it in one go.

Mornings are statistically the calmest part of the day. If you have a choice about when to be outdoors, that is the window.

There is an important exception worth knowing. Storms that organise into large clusters can survive long after sunset and roll through overnight. Overnight storms are more dangerous in practice — not because they are stronger, but because people are asleep and not watching the sky.

That is exactly why a point forecast with a real start hour beats a general outlook. Knowing a storm is due at 2 AM rather than 5 PM changes what you do about it.

Type your town into the tool below. You get the start hour, the peak, the duration, the strength of the storm signal, and separately the chance the cell slides past instead of passing overhead.

The model behind the forecast here is HRRR (NOAA, 3 km, aktualizacja co godzinę).

The radar above is a separate thing from the forecast. It shows what is actually falling and striking right now, minute by minute, up to two hours back. When the two disagree, trust the radar for the present moment and the forecast for the hours ahead.

Will you be warned? the USA issues official warnings through National Weather Service (NOAA). Emergency alerts reach phones in the affected area, but routine forecasts do not — for an ordinary storm you are relying on your own check.

• Do not disable emergency alerts in your phone settings — that is the channel that wakes you at night.
• In the open: get off high ground, open fields and beaches. Lightning strikes the highest point around.
• In a car: stay inside with the windows closed. The body shell acts as a Faraday cage.
• Not under a lone tree — a discharge can jump from the trunk to a person standing beside it.
• At home: unplug sensitive electronics if the building has no surge protection.

Do not drive into water on the road, and remember that flooding peaks after the rain stops, not during it. Water needs time to run off slopes and reach channels, so a creek can crest an hour or more after the last drop falls, under clear sky. Thirty centimetres of moving water reaches the underside of most cars; sixty floats many of them. More than half of flash-flood deaths happen in vehicles.

In an emergency call 911.

Storm timing is one thing; the wider week is another. The five-day outlook below covers temperature and the general character of each day — useful for deciding which day to travel or work outdoors in the first place.

• When will the storm end in the USA — duration and the all-clear
• Check the storm for your town