If you had your windows open last night you probably found yourself reaching for a blanket by first light this morning. The low temperature at BWI-Marshall was 59 degrees this morning. That was six degrees below the long-term average low for the date, but well short of the record low for a July 2 in Baltimore - 51 degrees set way back in 2001. Blankets in July are a good thing. They mean the AC is off and BGE's electric meters are barely turning.

It was 52 degrees at dawn on the WeatherDeck in Cockeysville, but a comparatively mild 63 degrees here at Calvert & Centre streets. Here are some overnight low readings from around the region: 

BWI: 59 degrees

Frederick Airport: 48 degrees

Dulles International: 59 degrees

Martin State Airport: 57 degrees

Ocean City: 55 degrees

Dover, DE: 53 degrees

Harrisburg, PA: 51 degrees

We can thank a Canadian high-pressure system for the cool, dry weather. And we'll have one more chilly night tonight, with a forecast low of 58 at BWI and good stargazing.

The high is moving from the Great Lakes south and east to the Atlantic coast. As the center gets past us, we'll fall once again under the return flow, which will bring winds from the South. And that means warming temperatures and rising humidities Tuesday night into Wednesday.

The Fourth should be hotter, but seasonably so, with highs at BWI in the upper 80s. We should not see any 90s this week, if the forecasters are right. Another cold front will droop south across the Mid-Atlantic states by Friday, bringing another chance for some showers. But don't look for any real relief from the persistent dry weather.

The forecast calls for temperatures to rise gradually during the week, with a slowly increasing chance of afternoon showers and thunderstorms. The weekend looks dry and pleasant.