High pressure will build across the St. Lawrence Valley through early this week, keeping the weather pleasant and dry through at least early Wednesday, according to the National Weather Service (NWS).

A frontal boundary will bring increasing chances for showers late Wednesday and Wednesday night but, at this time, the Fourth of July is expected to be mostly dry, NWS says.

Highs today will be around 81 with sunny skies, the service says. Overnight lows will be around 64.

Sunny skies early on Wednesday may give way to rain showers in the evening, forecasters say. Highs will be near 85.

The extended forecast through Monday is as follows:

Wednesday

Partly sunny, with a high near 85. South wind 7 to 14 mph, with gusts as high as 24 mph.

Wednesday Night

Showers likely, mainly before 2am. Mostly cloudy, with a low around 69. South wind 10 to 14 mph. Chance of precipitation is 70%. New precipitation amounts of less than a tenth of an inch possible.

Independence Day

Partly sunny, with a high near 84. West wind around 9 mph.

Thursday Night

Partly cloudy, with a low around 62. Southwest wind around 5 mph becoming calm in the evening.

Friday

Mostly sunny, with a high near 82. Calm wind becoming north around 5 mph in the afternoon.

Friday Night

A 50 percent chance of showers after 8pm. Mostly cloudy, with a low around 65. Light and variable wind becoming east around 5 mph after midnight.

Saturday Night

A 50 percent chance of showers. Mostly cloudy, with a low around 65. Southwest wind around 9 mph.

Sunday

A 30 percent chance of showers. Mostly sunny, with a high near 78. Southwest wind 9 to 11 mph.

Sunday Night

Partly cloudy, with a low around 64. South wind 5 to 7 mph.

Monday

A 30 percent chance of showers. Mostly sunny, with a high near 83. South wind 7 to 9 mph.