Activities planned for the Juneteenth holiday this year might have to contend with two of summertime's norms: thunderstorms – some possibly severe – and sweltering heat.

The federal holiday takes place on Thursday, June 19. It celebrates the abolition of slavery in the United States, specifically when the last enslaved people in Texas were told of their freedom on that date in 1865.

Here's what to expect:

Stormy Outlook

• Where Rain Is Possible: A cold front will track toward the East and South while teaming up with abundant moisture. The result will be showers and storms, most numerous in the afternoon and evening, stretching across parts of the Appalachians, Northeast and mid-Atlantic. The South is another region that could see storms, especially in the afternoon, but they might be hit-or-miss. The rest of the country should be dry, except for a few storms in the northern Great Lakes. Be sure to have a plan to shelter from lightning if you hear thunder and keep an umbrella handy in all of the above-mentioned locations.
• Severe Weather Is A Concern: Strong to severe thunderstorms are most possible from interior parts of New England and eastern New York southward through the Interstate 95 corridor to North Carolina. That includes New York City, Philadelphia, Raleigh and Washington, D.C. The biggest threats are damaging wind gusts, lightning and heavy downpours.

Temperatures

• Feeling Like Summer For Many: Whether it's temperatures climbing above average or high humidity, many parts of the country will want to take heat precautions if spending time outdoors. The Rockies, Southwest and adjacent Plains will see highs 10 or more degrees above average, which means 110-degrees plus in Phoenix and Las Vegas, low 100s in Salt Lake City and mid-to-upper 90s even in Denver. Much of the Northeast urban corridor will see highs peak around 90 degrees and the South will see plenty of its typical heat and humidity.
• Keeping Their Cool: The Pacific Northwest will see cooler weather with highs in the upper 60s and lower 70s in Seattle and Portland. Portions of the northern Great Lakes will also stay in the cooler 60s and 70s.

Chris Dolce has been a senior digital meteorologist with weather.com for 15 years after beginning his career with The Weather Channel in the early 2000s.