September's second work week begins with touches of autumn taking hold across more of the U.S. These details, along with our daily tropical outlook, are published every weekday at 5 a.m. ET.

The Northeast, Mid-Atlantic and the Midwest will need to get out the sweaters this morning. The TemperatureRadar shows lows in the 40s and 50s and highs in the 60s and 70s. This will definitely provide an autumn feel. Although the rest of the central Plains, South and Southeast will be slightly below normal, highs will still climb into the 80s.

The WeatherRadar shows a few afternoon thunderstorms will develop across Florida and the western high Plains. Showers are also possible across the northern Plains.

The western high Plains into the Rockies will be hot with highs in the 80s and low 90s, while the Southwest will be in the 90s and 100s. The Northwest and northern California will be cooler as clouds roll off the Pacific, with highs in the 60s and 70s. A few showers are possible.

The tropical system threat watched late last week and over the weekend has diminished. Additional development is not likely over the next several days.

The Atlantic Hurricane Season peaks in September, and you will want to be ready. Learn more about how our hurricane alerts work here.