Las Vegas faces a punishing stretch of dangerous heat this week, with the National Weather Service warning that temperatures will peak Tuesday and Wednesday and run 8 to 12 degrees above seasonal norms before a gradual cooldown arrives later in the week.

Meteorologist Julie Phillipson of the NWS Las Vegas office said afternoon highs across the Las Vegas Valley will climb into the lower 100s and beyond, with the most intense heat concentrated Tuesday and Wednesday.

The NWS forecast calls for a high near 107 degrees today, with overnight lows around 81. Tuesday and Wednesday are expected to be the most intense days of the stretch, with highs near 109 degrees both days and overnight lows near 81 and 83, respectively — offering virtually no relief after sundown.

“Major heat risk affects anyone,” Phillipson said during the agency’s weekly outlook briefing Monday, “not just those who are sensitive, but anyone who doesn’t have adequate access to cooling and hydration.”

The agency designated widespread moderate heat risk across the region for Tuesday and Wednesday, with pockets of major heat risk developing across the Las Vegas Valley and other desert communities — a threshold that also strains health systems and industries, Phillipson said.

The warm overnight lows are a key concern. Temperatures remaining in the low 80s through Wednesday night limit the body’s ability to recover from the daytime heat before another scorching afternoon arrives.

“That’s really going to limit the amount of relief that people can get,” Phillipson said.

Temperatures ease only slightly heading into the second half of the week — Thursday’s forecast high is 108 degrees, dropping to 105 on Juneteenth before falling to 102 over the weekend. Even so, minor to moderate heat risk persists through Sunday, the NWS said.

The agency’s 6-to-10-day outlook shows above-normal temperatures likely to continue through at least June 23.

Here are some tips to stay safe in the heat, including staying hydrated.