A heat advisory is in effect for St. Lawrence County from noon until 7 p.m. Friday with heat index values in the upper 90s expected, according to the National Weather Service (NWS).

Hot temperatures and high humidity may cause heat illnesses to occur, NWS says. Duration of the heat will be a factor, with similar temperatures and heat index values during the

peak heating hours both Thursday and Friday afternoon.

There will be widespread haze with sunny skies and highs near 93, forecasters say. Overnight the low will be around 73.

The high on Friday will be near 84 with light winds, the service says.

Take extra precautions if you work or spend time outside, NWS says. When possible reschedule strenuous activities to early morning or evening.

Know the signs and symptoms of heat exhaustion and heat stroke. Wear lightweight and loose fitting clothing when possible. To reduce risk during outdoor work, the Occupational

Safety and Health Administration recommends scheduling frequent rest breaks in shaded or air conditioned environments.

Anyone overcome by heat should be moved to a cool and shaded location. Heat stroke is an emergency. Call 911 if medical assistance is needed.

The forecast through next Wednesday is as follows:

Friday

Widespread haze after 9am. Mostly sunny and hot, with a high near 94. South wind around 6 mph.

Friday Night

A 30 percent chance of showers after 11pm. Mostly cloudy, with a low around 72. South wind 3 to 7 mph. New precipitation amounts of less than a tenth of an inch possible.

Saturday

Showers likely, mainly after noon. Mostly cloudy, with a high near 86. Calm wind becoming west around 6 mph in the afternoon. Chance of precipitation is 70%. New precipitation amounts between a tenth and quarter of an inch possible.

Saturday Night

Showers likely before 11pm, then showers likely and possibly a thunderstorm between 11pm and 4am, then showers likely after 4am. Mostly cloudy, with a low around 67. Southwest wind 3 to 6 mph. Chance of precipitation is 60%. New rainfall amounts between a tenth and quarter of an inch, except higher amounts possible in thunderstorms.

Sunday

Showers likely, with thunderstorms also possible after 1pm. Mostly cloudy, with a high near 81. Southwest wind around 6 mph becoming northwest in the afternoon. Chance of precipitation is 70%.

Sunday Night

Showers likely and possibly a thunderstorm. Mostly cloudy, with a low around 64. Light and variable wind. Chance of precipitation is 60%.

Monday

A 50 percent chance of showers. Partly sunny, with a high near 82. Northeast wind around 6 mph.

Monday Night

A 50 percent chance of showers before 3am. Mostly cloudy, with a low around 63. East wind around 7 mph.

Tuesday

A 40 percent chance of showers and thunderstorms. Partly sunny, with a high near 83. South wind 5 to 7 mph.

Tuesday Night

A 40 percent chance of showers and thunderstorms. Partly cloudy, with a low around 64. Light southwest wind.

Wednesday

Mostly sunny, with a high near 86. Southwest wind around 8 mph.