CHARLESTON, W.Va. (WCHS) — TUESDAY NIGHT UPDATE:

Charleston broke the record for the date from 1929, reaching 97 degrees Tuesday afternoon. Huntington's 105 degree record from 1930 was safe for another year.

However, it felt like 100 to 105 again in the afternoon as the humidity remained high.

That marks the third straight day of 100+ heat index readings and Wednesday will mark four in a row, putting us in rare territory.

Heat index readings up around 100 or higher are expected through Friday although some locations can come up short as some small but torrential downpours and storms pop up in some locations. These will become more common later in the weekend.

MONDAY AFTERNOON UPDATE:

Sunday marked the start of what may end up being our region's worst heat wave since the 1930s.

Extreme heat is coming early in the season after a relatively mild spring, coinciding with the strongest sun angle of the year, making for a potentially deadly combination.

We've had hotter days in terms of temperature. In fact we reached 90+ degrees 48 times between June 1 and August 31 last year.

However, because of the developing drought around this time last year only two of those 90-degree days had afternoon dewpoints of 70 or higher.

The hot summer of 1988 also featured many 90 and 100-degree days but low humidity for the most part.

Because of record rains in May and June, an enormous amount of moisture in the ground is getting pumped back into the air.

Dewpoints of 70 to 75 degrees will be common this week. That means 95 degrees won't feel like 95. It will feel more like 100 to 110 degrees.

We've had heat indices that high before but usually for a day or two.

Now we could be looking at a solid week of heat index numbers well above 100 which has never happened in our region in recorded history.

How long this stretch goes on will ultimately be determined by storm development later in the week and weekend.

Outdoor activities should be put off until temperatures can back off, maybe by the weekend. That includes going to pools, doing yardwork or attending any outdoor events. Spend as little time as possible outdoors and find an air-conditioned space to ride out this unprecedented event.

As a ridge of high pressure begins to weaken later this week the chance for scattered thunderstorms will increase.

While these can knock down afternoon temperatures for areas that see them, they will also turn violent, capable of producing 70+ mph winds and torrential rain that can lead to flash flooding.

The threat for severe storms will be more widespread by this upcoming weekend as a slow-moving cold front approaches from the north.

It will remain hot and humid, although numbers will likely be lower compared to the workweek.

A weather alert is in effect into next week for multiple weather threats.