National Weather Service

Perhaps beginning as soon as Wednesday, the Bay State may have to confront the first heat wave of the year, said Bill Simpson, a meteorologist for the National Weather Service in Taunton.

Today, the heat will likely be more moderate with temperatures in the mid to upper 80s, Simpson said. It will be slightly cooler around the coast and on the Cape and the islands.

A lower dew point than yesterday will give the region a comfortable level of humidity today. There is a low chance of showers in the afternoon, most likely across the southeastern part of the state.

Wednesday should look like today, though possibly a few degrees warmer – there’s a chance temperatures could reach 90 - and with higher humidity in the afternoon. It should be sunny with no precipitation.

But if the temperature does break into the 90s, Wednesday could be the first part of a heat wave, which is defined as three consecutive days of temperatures at 90 degrees or above.

Meteorologists said that unless there is a dramatic change in weather conditions, Thursday and Friday will both be hot and humid with temperatures in the mid to upper 90s on both days. The tough weather may continue into Saturday, the weather service says.

Heat indexes take humidity into account, giving a picture of what the temperature feels like regardless of what the thermometer says.