Tradewinds weaken to the light and moderate range today and will remain so through the rest of the week in the Hawaiian islands, according to National Weather Service officials.

This is due to an “unseasonably strong low pressure system” in the Gulf of Alaska, far to the northeast of the isles, which will keep the high-pressure ridge north of the state in a weakened state. Trades flowing out of this ridge will remain light to moderate through Friday.

Today will be mostly sunny and hot, with highs from 89 to 94 degrees Fahrenheit and winds from 5 to 15 miles per hour. Isolated showers are expected in the afternoon and evening.

High humidity levels will boost the heat index, a reflection of what it feels like when temperature and relative humidity are combined, to a high level today.

The heat index is expected to reach as high as 102 degrees in Honolulu, particularly in the Kakaako area, 100 in Kahului, 98 in Kapolei and 95 in Lihue this afternoon.

On Tuesday, three more temperatures matched record highs from years past, as far back as 38 years ago. A record high of 89 degrees in Lihue tied with the record set in 1981. A record high of 92 degrees in Honolulu tied with the one set in 2005. A record high of 89 degrees in Hilo tied the one set in 2015.

Record highs and ties in temperatures have been set nearly every day on various isles since the start of August, continuing a trend that began in May.

Increasing moisture and showers are possible for this weekend.