How many states and US Territories have an average of 0-10 tornadoes per year?

Answer 1

Based on data from 1991-2011, the following 19 states and territories have averaged 10 or fewer tornadoes per year. Note that a zero for number of tornadoes doesn't mean no tornadoes, it merely means an average of less than one every two years.

Arizona (5 per year)

Idaho (5)

Oregon (3)

Utah (3)

Washington (3)

New Jersey (2)

West Virginia (2)

Maine (2)

Nevada (2)

Connecticut (2)

Massachusetts (1)

Delaware (1)

New Hampshire (1)

Vermont (1)

Hawaii (1)

Puerto Rico (1)

Rhode Island (0)

Alaska (0)

Washington D.C. (0)
There are 22 states that average less then 10 tornadoes per year.

The are:

Alaska, Arizona, California, Connecticut, Delaware, Hawaii, Idaho, Maine, Maryland, Massachusetts, Montana, Nevada, New Hampshire, New Jersey, New Mexico, New York, Oregon, Utah, Rhode Island Vermont, Virginia, and Washington.
The states states fit this criterion based on tornado data averaged from the years 1991-2011 are:

Montana (10 tornadoes per year)

Arizona (5)

Idaho (5)

Utah (3)

Washington (3)

Oregon (3)

New Jersey (2)

West Virginia (2)

Maine (2)

Connecticut (2)

Nevada (2)

Massachusetts (1)

Delaware (1)

Note that these are only averages, and that the number of tornadoes a state gets in a year can vary. Also note that there are several states not on this list that average less than 1 tornado per year .

Answer 2

Nine states and one US territory have an average of 0-10 tornadoes per year. These states include Alaska, Hawaii, Rhode Island, Delaware, Vermont, New Hampshire, Connecticut, Massachusetts, and Maryland. The US territory is Washington D.C.