Tornadoes occur on all continents except Antarctica. They are most common in the middle latitudes where warm and cold air masses frequently collide, creating conditions favorable for convective storms. The United States experiences the most tornadoes, especially in an area called Tornado Alley in the central US. Canada has the second-highest frequency of tornadoes, particularly in Ontario and the Prairie Provinces. Other notable regions with frequent tornadoes include parts of Europe (such as the Po Valley in Italy and some areas in Germany and the UK), South Africa, Bangladesh and eastern India, the Philippines, Argentina, Uruguay, southern and southeastern Brazil, northern Mexico, Australia, New Zealand, and parts of eastern Asia. Tornadoes tend to form in areas where warm tropical air meets cooler polar air, typically between 20° and 60° latitude in both hemispheres. They can occur throughout the year but are most common in spring and summer months. Summary by continent and notable regions:
- North America: USA (Tornado Alley), Canada (Ontario, Prairies), northern Mexico
- South America: Argentina, Uruguay, southern Brazil, Paraguay
- Europe: Po Valley (Italy), Germany, UK, some areas of France and Spain
- Asia: Bangladesh, eastern India, Philippines, China, Japan
- Africa: Southern Africa including South Africa, seasonal occurrences in western Africa
- Oceania: Australia, New Zealand
No tornadoes occur in Antarctica due to lack of suitable atmospheric conditions.
