AUSTIN (KXAN) — Gas prices in Texas continue to decline from record highs earlier this summer.

A gallon of regular unleaded gas now costs an average of $3.56 across the state, down 15 cents from last Monday.

There is still quite a bit of variation across the state. Drivers in College Station are paying the most at the pump: an average of $3.80 a gallon.

Meanwhile, drivers in the Rio Grande Valley are enjoying the cheapest gas in the state. Both the Brownsville-Harlingen and McAllen metro areas are averaging $3.25 a gallon as of Monday.

A year ago, El Paso had the most expensive gas, at $3.22 a gallon. At that time, Texas drivers were paying an average of $2.84.

According to AAA, there are several factors that explain why some cities see higher gas prices. Individual retailers set their own prices, so local supply and demand can cause prices to change more quickly in some parts of the state compared to others. Distribution costs can also factor in.

While prices are still higher than this time last year — by an average of 72 cents across the state — Texas has seen considerable improvement since record highs seen in June.

The state average peaked at $4.70 on June 15. Since then, prices have dropped by $1.14 to an average of $3.56.

The map below shows how prices have dropped since the June records. The darker the blue, the more cost savings that metro has seen.

Prices have decreased the most in the Sherman-Denison metro, north of Dallas. Prices there have dropped by $1.48 from a record high of $4.82 on June 16.

In Austin, prices are down $1.11 since a record of $4.70 on June 14. Drivers here are now paying $3.59 a gallon on average.

Prices in Midland have decreased the least — down 78 cents since the peak — but the metro didn’t see prices quite as high as elsewhere. The peak in Midland was $4.52 on June 11.

The statewide average of $3.56 means Texas now has the cheapest gas in the nation.

Across the country, 23 other states now have averages below $4 a gallon.

Only Hawaii and California remain above $5 a gallon, at $5.42 and $5.45 respectively.