Low-cost states
Average monthly price: $137
Total six-month policy average: $817
States included: Idaho, Indiana, Iowa, Kansas, Maine, Minnesota, Montana, New Hampshire, New Mexico, North Carolina, North Dakota, Ohio, Oklahoma, South Dakota, Vermont, Wisconsin, and Wyoming.
Why these are the most affordable states
Favorable weather: Most of these states aren't coastal, which means you're not as susceptible to catastrophic weather such as hurricanes. Plus, these are non-desert states, which means chipped/cracked glass claims aren't as common. Glass claims are usually caused by debris/rocks being kicked up cars, and that happens more frequently in dry, desert states.
Small population density: Fewer drivers leads to less congested roads, lower traffic, and ultimately fewer accidents.
Low crime rates: For vandalism and car thefts, these states generally rank lower than medium and high-cost states.
Lack of dangerous intersections: Insurance companies track data on particularly dangerous intersections, such as five- and six-way stops, really busy intersections, etc. These states tend to have fewer, which means fewer accidents.
Insurance requirements are minimal: So insurance companies pass the savings on to drivers.
Medium-cost states
Average monthly price: $167
Total six-month policy average: $999
States included: Alaska, Arizona, Alabama, Arkansas, Hawaii, Illinois, Kentucky, Mississippi, Missouri, Nebraska, Nevada, Oregon, Tennessee, Utah, Virginia, Washington, and West Virginia.
Why these states rank in the middle per cost
Fairly favorable weather: Most states in this group aren't coastal, so you're not susceptible to catastrophic weather. But, desert and other dry states may be prone to glass damage from debris/rocks being kicked up by cars.
Fairly populated: These states fall in the middle in terms of population, which means they also fall in the middle for traffic and accidents.
Medium crime rates: For vandalism and car thefts, these states generally rank lower than high-cost states but higher than low-cost states.
Fewer dangerous intersections: Compared to high cost states, most states ranking in the middle per cost don't have as many risky intersections—which means fewer accidents.
Some insurance requirements by state law: These aren't the most regulated states, but may have more mandates that could increase insurance prices compared to low-cost states.
High-cost states
Average monthly price: $232
Total six-month policy average: $1,379
States included: California, Colorado, Connecticut, Delaware, District of Columbia, Florida, Georgia, Louisiana, Maryland, Massachusetts, Michigan, Pennsylvania, New Jersey, New York, Rhode Island, South Carolina, and Texas.
Why these are the most expensive states
Dense population: More drivers mean more accidents.
Severe weather issues: Earthquakes, floods, and hurricanes are more common, as many of these states are coastal. Plus, many of these non-coastal states are more prone to hail, which leads to more claims.
Higher crime rates: Theft and vandalism are more common in this group of states than medium- and lower-priced states, which results in more claims.
More dangerous intersections: Busy five- and six-way stops are likely to cause more accidents.
More stringent insurance requirements by state laws: Many of these states have highly regulated insurance laws or more complex coverage requirements. That means higher prices.
Source: https://www.progressive.com/answers/average-car-insurance-cost/