HUNTSVILLE — The 1966 classic “Hot Time, Summer in the City” will live up to its name this week.

And it will also be a hot time in the country, on the river, lakes and even the mountains.

With temperatures expected to reach 100 degrees and heat index values up to 115 degrees, the National Weather Service Huntsville Office issued an excessive heat watch for Thursday for a large portion of North Alabama and Southern Middle Tennessee.

But the watch may be amplified.

“We expect to issue either Excessive Heat Warnings or Advisories for Thursday, Friday into Saturday at some point,” the office said.

“Heat Index Values of 105-114 degrees are expected for many areas.”

The weather service said to expect some relief from the heat by Sunday into early next week.