Hazardous heat indices expected to exceed 43.3 °C (110 °F) from Plains to Southeast, dangerous heat building in the West

The National Weather Service has forecasted hazardous heat spreading from the Plains through the Mississippi Valley to the Southeast starting this week and continuing into the next. High temperatures combined with high humidity are expected to produce dangerously high heat indices, potentially exceeding 43.3 °C (110 °F).

The National Weather Service (NWS) forecasts the spread of hazardous heat from the Plains through the Mississippi Valley to the Southeast this week, continuing into next week.

The high temperatures, exceeding 38 °C (100 °F), paired with high humidity will result in dangerously high heat indices that could exceed 43.3 °C (110 °F) at times across the Plains, Mississippi Valley, and the Southeast.

The hazardous heat will spread through the middle and lower Mississippi Valley from the central and southern Plains by midweek and expand into the Southeast and mid-Atlantic late this week.

The NWS forecasts multiple days of extreme heat risk from the Plains to the Southeast.

In addition, intense and widespread heat will build across the western USA late this week due to an upper-level high-pressure system and is likely to persist into the coming week.

High temperatures are expected to be 5.6 – 8.3 °C (10 – 15 °F) higher than normal across the Northwest and northern High Plains by August 2, with the forecast of several daily record high temperatures.

The risk for heat-related illnesses will be high due to the prolonged nature of the excessive heat, which will expand across the West over the weekend and is likely to persist into next week.

The hot and dry conditions will maintain fire weather concerns, causing a looming threat of wildfires, particularly with the winds associated with the high-pressure center that will set up over the Intermountain West on August 2.