In the united states, what regions are most at risk for tornados and hurricanes, and why?

The region that's most likely at risk for a tornado is Tornado Alley. Tornado Alley consists of these U.S. states: Texas, Oklahoma, Kansas, South Dakota, Iowa, Illinois, Missouri, Nebraska, Colorado, North Dakota, and Minnesota. These states unfortunately are at the most risk of tornadoes. This is because the region allows cold air (from Canada) meet with moist and warm air (from the Gulf of Mexico), so it's soon in between two the air-masses that most tornadoes eventually form.

The region most at risk for hurricanes are states along the South; the most common places at risk are Texas, Florida, and Louisiana. You're more likely to get hit by a hurricane in these states. This is because of the mere influence from low pressure systems that cause high wind speeds on tropical systems.