U.S. Drought: Weekly Report for January 31, 2023

According to the January 31, 2023 U.S. Drought Monitor, moderate to exceptional drought covers 35.7% of the United States including Puerto Rico, a decrease from last week’s 36.0%. The worst drought categories (extreme to exceptional drought) slightly decreased from 6.3% last week to 6.2%.

During this U.S. Drought Monitor week (January 25-31), a strong ridge of high pressure in the upper atmosphere over the eastern Pacific blocked Pacific weather systems from entering the western U.S. A northerly flow at the jet stream level funneled cold Canadian air into the Great Plains and western contiguous U.S. This combination of features gave the West a cooler- and drier-than-normal week. 

Low pressure systems were directed by the jet stream flow into the central contiguous U.S. where they generated above-normal precipitation across the northern Rockies to the northern Plains. Some of the fronts and low-pressure systems penetrated into the southern Plains. From there, they tapped Gulf of Mexico moisture to spread rain and snow across parts of the southern Plains and much of the Southeast. As the weather systems tracked northeast, they dropped above-normal precipitation over parts of the Ohio Valley and Northeast regions. Parts of the central Plains to western Great Lakes, parts of the interior Northeast, and much of Florida remained drier than normal. East of the Rockies, temperatures averaged cooler than normal over the Plains and warmer than normal across the East. 

Drought or abnormal dryness contracted across parts of the West, Plains to Midwest, Southeast Coast, and Hawaii. Drought or abnormal dryness expanded in a few other parts of the West and southern Plains, as well as Florida. Nationally, contraction exceeded expansion, with the nationwide moderate to exceptional drought area decreasing this week.

Abnormal dryness and drought are currently affecting over 139 million people across the United States including Puerto Rico—about 44.8% of the population.