This Memorial Day weekend in the North Country will be hot, with possibly record-breaking high temperatures today and tomorrow.

With highs on the order of 10 to 20 degrees above normal, National Weather Service forecasters say highs today will be near 90, which is one degree hotter than the 89-degree high recorded at Massena’s airport on this date in 1978. A day later, on May 29, 1978, a record high in Massena of 90 was set.

Higher dew points will lead to more humid conditions and the threat of showers and thunderstorms, especially on Sunday and Memorial Day.

The first half of today should be partly sunny with warm and modestly humid conditions with widely scattered showers and isolated storms mainly at higher elevations. Lows tonight will be about 65.

More widespread rain and showers could develop Sunday and especially Sunday night, the NWS says, when heavy rain could appear. Highs Sunday are expected to approach 90 degrees, and lows Sunday night will drop to the mid-60s.

For Memorial Day, the chance of showers continues with maybe thunderstorms, and it will be cooler and not as humid, with highs around 80.

You can keep track of weather developments through the resources on our weather page, www.northcountrynow.com/weather.

The NWS forecast for the St. Lawrence Valley and northwestern Adirondacks:

• Today: Mostly cloudy and hot, with a high near 90. West wind around 7 mph.

• Tonight: Partly cloudy, with a low around 65. Light and variable wind.

• Sunday: A 30 percent chance of showers and thunderstorms, mainly after 2pm. Some of the storms could produce heavy rain. Partly sunny, with a high near 89. Light and variable wind becoming southwest 5 to 10 mph in the morning. New rainfall amounts of less than a tenth of an inch, except higher amounts possible in thunderstorms.

• Sunday Night: A chance of showers and thunderstorms. Some of the storms could produce heavy rain. Cloudy, then becoming partly cloudy toward daybreak, with a low around 67. South wind 3 to 7 mph. Chance of precipitation is 50%. New precipitation amounts of less than a tenth of an inch, except higher amounts possible in thunderstorms.

• Memorial Day: A chance of showers before 1pm, then a chance of showers and thunderstorms between 1pm and 2pm. Partly sunny, with a high near 81. Southwest wind 10 to 15 mph. Chance of precipitation is 30%. New rainfall amounts of less than a tenth of an inch, except higher amounts possible in thunderstorms.

• Monday Night: Partly cloudy, with a low around 59. Southwest wind 7 to 10 mph.

• Tuesday: Mostly sunny, with a high near 79. West wind 7 to 11 mph.

• Tuesday Night: Mostly clear, with a low around 56. Northwest wind around 6 mph becoming calm in the evening.

• Wednesday: Sunny, with a high near 80. Light north wind.

• Wednesday Night: Mostly clear, with a low around 57. Light and variable wind becoming southeast around 5 mph after midnight.

• Thursday: Mostly sunny, with a high near 84. South wind 6 to 8 mph.

• Thursday Night: A 30 percent chance of showers. Mostly cloudy, with a low around 60. South wind around 8 mph.

• Friday: A 40 percent chance of showers. Partly sunny, with a high near 78. South wind around 10 mph.