The dry spell in Boston and Eastern Massachusetts is mainly due to a persistent “high-pressure system” — think clear skies and sunny weather — as opposed to “low-pressure systems” which bring heavy clouds and rainfall, according to Kyle Pederson, a meteorologist for the National Weather Service.

Unless our weather pattern changes, those areas already excessively dry could be headed into a full-blown drought.

Bring a pattern change from sunny, warm and dry to cloudier, cooler and wet at times. Light rain and drizzle move in tonight with off and on rounds of rain coming i