Millions of Americans Will be Left Sweating as Heat Wave Grips the Nation

The new week is going to kick off where the weekend ended, with a dangerous heat wave continuing to expand to the east. Approximately 170 million Americans will be in the crosshairs of the extreme heat through the end of the month. Here is a look at the sizzling week ahead.

Heat Wave Expands to the East as New Week Begins

Daily record highs are expected to fall across the central and eastern portions of the U.S. as the mercury continues its upward trajectory. Nighttime lows will remain elevated, resulting in little relief from the heat in the Plains states and over to the East Coast. Ovenright lows will remain above 80 degrees for several nights in a row for many cities. The elevated nighttime readings will inherently increase the threat of heat-related illnesses, particularly in homes without air conditioning.

In addition to the rising temperatures, an increase in the humidity levels will make it feel even toastier. High readings are forecast to climb into the triple digits across about three dozen states. The extreme heat will persist through at least the middle of the week.

The heat dome that set up over the central U.S. to end the week will stretch to the east as the new week kicks off. The Northeast and the mid-Atlantic will be in the bullseye for the core of the heat beginning on Monday. The humidity and the intense sunshine will amplify the heat.

Most of the largest urban areas along the East Coast are forecast to see the mercury reach the upper 90s or the 100-degree threshold for a few days in a row. Should this forecast come to fruition, it will be the first time in decades that temperatures have hit the century mark in the month of June for this part of the nation.

New York City is bracing for a high of 101 degrees on Tuesday under mostly sunny skies. Local officials are worried that many residents will need to wait outside to vote in the city's mayoral primary election on this day. Those planning to exercise their right to vote should be prepared with plenty of water and loose-fitting clothing.

New England will also get in on the heat. This is an area of the U.S. that does not typically see heat of this magnitude. Boston is forecast to see a top reading of 101 degrees on Tuesday after reaching the low 90s on Monday. Tuesday's forecast in Boston is calling for winds out of the west at 10 to 20 mph, helping to provide just slight relief.

Moving to the north, Portland, Maine, will top out with readings in the mid 90s on Tuesday. This is a part of New England that is not accustomed to heat of this magnitude, meaning that many homes lack air conditioning. Relief will arrive by Thursday in Portland with a forecast high of just 73 degrees. By Friday, the mercury will struggle to climb out of the mid 60s for a high.