Prices are rising around the Twin Cities too. After several fills where I only paid between $3.539 and $3.659, today the cheapest I could find was $3.729. And most stations were charging $3.85-3.89/gallon.
Over the last 2 1/2 to 3 weeks, WTI crude has risen from about $79/barrel to over $92, while Brent crude is up from $93 to about $107. A lot of oil processed by US refineries, such as Louisiana Sweet and Alaska North Slope crudes, are priced about the same as Brent.
Over that same period, RBOB gasoline futures are up about 40 cents/gallon, from $2.52 to $2.92, while heating oil futures are up about 34 cents, from $2.60 to $2.94.
eTrucker says the average price of diesel is about $3.72 nationally. AAA says it's $3.703, up from a week ago but down from a month ago.
I think there are more price increases to come, so I recommend filling up whenever and wherever you see a good price. I don't think prices will go much higher, but I could be wrong. So fill up now and keep it full.