Long Island weather: Sunny with highs in the 60s

Sunny skies are expected Saturday and Sunday, with highs during the day reaching the mid-60s, forecasters said, as autumn tightens its grip — especially during the nights, which are becoming markedly cooler.

"Tonight, temperatures in far outlying northern and eastern areas of the tri-state will radiate into the upper 30s, with some patchy frost even possible," the National Weather Service’s Islip office said. "Elsewhere, overnight lows will be at or below normal."

Lows in the 40s are predicted on Long Island Saturday night, the weather service said.

The work week likely will start off Monday with an umbrella mandate, but the Tuesday to Friday period all should be bright and clear.

Ahead of that, there is a 40% chance of showers after midnight Sunday and a 50% chance during the day on Monday, the weather service said.

"Unseasonably cool conditions likely Monday with shower activity and breezy north/northeast flow (particularly coast and east), with temps potentially struggling to get into the 60s for part of the region," the weather service said.

Monday night‘s clouds will keep the night from cooling down as much — thermometers likely will only fall to the low 50s, the weather service said.

By sending the jet stream south, Canada is contributing to the cool down, which should make the outdoors inviting for the rest of the workweek.

"The next piece of jet energy dives south and east across the Great Lakes and Ohio Valley states Monday night into Tuesday, sending a cold front toward the region for mid week," the weather service said.

Highs are expected to be in the upper 60s on Tuesday, the weather service said.

Wednesday’s temperatures could approach the 70s, and that likely will be the high for the week.

"All other days through the period will be in the 60s with the coldest day coming next Friday (closer to 60)," the weather service said. "Lows will generally be in the upper 40s well inland to the mid-50s" for the metropolitan area.

The coldest morning will be Friday, the forecasters said, "with lows ranging from the upper 30s to upper 40s."