High heat and thunderstorms will again be the main weather stories across the nation on the Fourth of July, forecasters say, but conditions will not be as intense or widespread as in recent days.

However, potentially record-breaking heat will make for a sweltering holiday in portions of the western U.S., especially the normally mild Pacific Northwest, where high temperatures will approach 100 degrees in Oregon.

The greatest threat for severe weather on the Fourth will focus on the central and northern Plains, where thunderstorms could produce damaging winds and large hail late in the day and at night, AccuWeather said.

Western heat wave continues

The Desert Southwest and West Coast will continue to sizzle on the Fourth, the National Weather Service said.

Record-breaking heat is forecast to scorch northern California and western Oregon on Tuesday. Highs areforecast to reach into the 90s and low 100s, the weather service said.

AccuWeather predicts that temperatures are projected to challenge daily record highs along portions of I-5, ranging from near 90 degrees in Seattle to the lower 100s in Medford, Oregon.

Highs well into the triple digits are also forecast throughout the Desert Southwest. An excessive heat warning is in effect Tuesday in both Phoenix and Tucson in Arizona, the weather service said.

Elsewhere, “it’ll be another day with plenty of the heat and humidity July is known for in the Southeast, Plains, Midwest and parts of the Northeast,” according to Weather.com meteorologist Chris Dolce.

Heat news:Everything you need to know about heat: From the heat index to a heat dome to an excessive heat warning

Heat index forecast map