Summer officially began today, but thermometers across the Upstate and other portions of South Carolina say otherwise.

For much of the past two weeks, the Palmetto State has endured temperatures in the mid- to upper-90s, prompting local residents to flee indoors in an effort to keep cool.

“Temperatures are definitely above normal, a consistent trend over the course of the past week,” said Philippe Papin of the National Weather Service. “For this time of year we are used to getting a 90-degree day here and there, but for it to go on for days at a time is quite unusual.”

According to observations obtained by the National Weather Service, the mercury has risen above the 90- degree threshold five times since June 10. Local residents can expect more of the same during the coming week, as daytime highs are expected to hover around 90 degrees.

Remarkably, temperatures in recent days were not hot enough to qualify for record highs, Papin said.

Though thermometer readings occasionally venture above 90 during June, temperatures typically average from the low- to mid-80s for the month.

Other portions of the state are not exempt from the recent heat wave, including Columbia, which reported a high temperature of 100 last week.

“Columbia and surrounding areas were placed under heat advisories at various times this week,” Papin said. “It’s definitely dangerous to stay out in the heat for extended periods of time. The chance for heat exhaustion and heat stroke definitely increases the longer you are exposed.”

Excessive heat is the top weather-related cause of death in America. When the heat index surpasses the 100-degree mark, people are at an increased risk of heat stroke, heat cramps and heat exhaustion.

“Heat is definitely a big issue, particularly when the heat index approaches 100 degrees and warmer,” Papin said.

Approximately 175 people die each summer from heat-related illnesses.