Summer begins with an extreme heat watch in effect for Long Island from Sunday afternoon through Tuesday evening.

It will be mostly cloudy and mild, with lows near 67 degrees overnight.

Saturday begins with mostly cloudy skies, but the day will turn nice and sunny, with less wind. It will be very warm, with highs near 85 degrees.

Temperatures are on the rise for Sunday, with highs nearing 90 degrees and heat indices near 100.

That's the kind of weather we will have around through at least Tuesday of next week so prepare to take precautions to stay hydrated and keep cool.

Expect sunshine, with hot and humid conditions through the start of next week with a potential heat wave.

Temperatures will cool down to seasonable levels by the end of next week with highs in the upper 70s to near 80 degrees.

OVERNIGHT: Mostly cloudy, with lows near 67 degrees. West southwest wind 5 to 10 mph. Sunrise: 5:21 a.m.

SATURDAY: Morning clouds then mostly sunny and very warm. Highs near 85 degrees. Southwest wind 5 to 10 mph. Sunset: 8:27 p.m. Partly cloudy and warm at night, with lows near 70 degrees. South winds 5 to 10 mph.

SUNDAY: Mostly sunny, hot and humid. Highs near 90 degrees, with lows near 74 degrees.

MONDAY: Mostly sunny, hot and humid. Highs near 92 degrees. Lows near 75 degrees.

TUESDAY: Mostly sunny, hot and humid. Highs near 94 degrees. Lows near 73 degrees.

WEDNESDAY: Mostly sunny. Not as hot, with highs near 88 degrees. Lows near 68 degrees.

THURSDAY: Mostly sunny and seasonable. Highs near 80 degrees. Lows near 67 degrees.