DENVER (KDVR)– Gas prices continue to rise across the country. The national average for a gallon of gas rose above $4.00 on Monday morning.

According to AAA, the national average for a gallon of regular fuel was $4.06.

Here are the least expensive states for gas as of Monday morning at 10 a.m. EST:

  1. Missouri: $3.62
  2. Oklahoma: $3.64
  3. Kansas: $3.67
  4. Arkansas: $3.69
  5. South Dakota: $3.70
  6. Iowa: $3.71
  7. Texas: $3.72
  8. Nebraska: $3.73
  9. North Dakota: $3.73
  10. Wyoming: $3.74
State Regular Mid-Grade Premium Diesel 
South Dakota$3.701$3.802$4.153$4.148
North Dakota$3.732$3.942$4.204$4.193
Credit: AAA

Even though these states have the lowest average gas prices in the country, according to AAA, they have all seen a significant rise in prices week-to-week.

Here’s a look at how much prices have risen since last week, according to AAA:

  • Missouri: up $.30
  • Oklahoma: up $. 36
  • Kansas: up $.30
  • Arkansas: up $.46
  • South Dakota: up $.26
  • Iowa: up $.32
  • Texas: up $.44
  • Nebraska: up $.32
  • North Dakota: up $.33
  • Wyoming: up $.30

California is the most expensive state for gas with an average price of $5.34 per gallon for regular, followed by Hawaii ($4.69) and Nevada ($4.59).

The Associated Press said the all-time high for average gasoline prices was set in July 17, 2008, at $4.10 per gallon.

GasBuddy, which tracks prices down to the service-station level, said Monday that the U.S. was likely to break its record price of $4.10 a gallon, but that does not account for inflation. In today’s terms, the record price would be equal to about $5.24 after accounting for inflation.

“Forget the $4 per gallon mark, the nation will soon set new all-time record highs and we could push closer to a national average of $4.50,” said GasBuddy analyst Patrick De Haan. “We’ve never been in this situation before, with this level of uncertainty. … Americans will be feeling the pain of the rise in prices for quite some time.”

Oil prices soared early Monday before retreating. In midday trading, benchmark U.S. crude was up 2% to about $118 a barrel, and the international price gained 4% to around $123 a barrel. Major U.S. stock indexes were down about 2%.

The Associated Press contributed to this report.