Mainly cloudy, warm and muggy with patchy fog and a passing shower overnight. Lows into Friday morning will be in the upper 60s to lower 70s.

Thursday is the next weather day with multiple risks for Long Island. First, be safe with the extreme heat and poor air quality. You will feel the heat and humidity building quickly on Thursday morning. It will feel uncomfortable outside, but it will be a dry start to the day. With heat advisories posted, and now extended through Friday evening, and an air quality alert in effect Thursday, please do not overexert yourself and take breaks from the high heat and humidity.

That heat and humidity will act as fuel to help spark scattered downpours and strong thunderstorms in the afternoon and evening. This can impact the evening commute with scattered flooding and a chance for storm-related damage. A spotty thunderstorm is possible at any time in the afternoon and evening, but the best chance for any severe thunderstorms is likely to be after 5 p.m. Be safe and stay with News 12 Long Island for updates throughout the day on the storm chances and heat. An important thing to keep in mind is that not everyone will get severe weather, but the weather parameters for strong to severe thunderstorms are there for Nassau and Suffolk Counties on Thursday.

OVERNIGHT: A passing shower, otherwise mostly cloudy, warm and muggy with patchy fog and low temperatures in the upper 60s to low 70s into Thursday morning. Wind: Breezy - southwest 10 to 20 mph.

THURSDAY: STORM WATCH - HEAT ADVISORY - It will heat up in a hurry, and you will feel uncomfortable levels of humidity with a mix of sun and clouds to start the day. Highs in the upper 80s to low 90s can feel close to 100 degrees at times. Please stay heat smart, drink plenty of water and take frequent breaks. There can be a pop-up shower or gusty thunderstorm at any point in the afternoon, but the best chance for strong to severe thunderstorms will be after 5 p.m. and through the evening. UV index: 9 (very high). BOATERS: Use extreme caution in the afternoon and evening as that storm chance increases. Stay with News 12 Long Island for updates on-air, on social media and the News 12 app. Lows - warm and muggy - around 69 degrees into Friday morning.

FRIDAY: HEAT ADVISORY - POTENTIAL STORM WATCH - Sun and clouds, hot and humid again. Highs in the upper 80s can once again feel like the middle 90s. Please use caution and enjoy the dry start to the day safely by not overexerting yourself and continuing to stay hydrated. There is a chance for a late-afternoon and evening shower or gusty thunderstorm. Lows near 68 degrees.

SATURDAY: NOT AS HUMID -- Sun and clouds. Hot, but feeling slightly less uncomfortable with lower humidity. Highs around 89 degrees. Lows near 66 degrees.

SUNDAY: Sun and clouds. Slight chance for a late-day shower or thunderstorm. Highs around 86 degrees. Lows near 65 degrees.

MONDAY: A few showers. Otherwise, partly sunny with highs around 83 degrees. Lows near 63 degrees.

TUESDAY: Partly sunny with a few afternoon and evening rain showers. Highs around 78 degrees. Lows near 64 degrees.

WEDNESDAY: Partly sunny with highs around 75 degrees. Lows near 64 degrees.

THURSDAY: Mostly sunny. Highs around 79 degrees. Lows near 66 degrees.