According to the December 3, 2024 U.S. Drought Monitor (USDM), moderate to exceptional drought covers 36.5% of the United States including Puerto Rico, an increase from last week’s 34.7%. The worst drought categories (extreme to exceptional drought) decreased from 4.1% last week to 3.9%.

The upper-level circulation pattern over the contiguous U.S. (CONUS) during this U.S. Drought Monitor (USDM) week (November 27–December 3) consisted of a broad ridge of high pressure over the West with a trough of low pressure over the East. The ridge inhibited precipitation over the West, while a northwesterly flow between the ridge and trough inhibited precipitation over the central and eastern parts of the CONUS. 

A Pacific weather system early in the week gave parts of the central Rockies above-normal precipitation. It moved quickly eastward, bringing precipitation to parts of the Ohio Valley and Northeast. Other disturbances moving through the trough generated precipitation over parts of the northern Plains, Great Lakes, and Northeast. Otherwise, the week was mostly dry. The eastern trough sent strong cold fronts plunging across the Plains to East and Gulf Coasts, giving most of the country east of the Rockies a colder-than-normal week, while the Pacific weather system and a lingering snowpack kept temperatures cooler than normal over much of the West.

The week was mostly drier and cooler than normal in Alaska and Hawaii, and warmer and mostly drier than normal across Puerto Rico and the U.S. Virgin Islands.

Drought and abnormal dryness contracted or reduced in intensity in parts of the West, northern Great Plains, Great Lakes, and central Appalachians where precipitation fell. Drought or abnormal dryness expanded or increased in intensity in some of the dry areas, including a few parts of Hawaii, the Rockies, and Lower Mississippi and Tennessee Valleys; much of the Carolinas and Virginia; and northern parts of the Northeast which missed out on the precipitation this week.

Nationally, expansion was more than contraction, so the nationwide moderate to exceptional drought area percentage increased this week, although the area experiencing abnormal dryness and drought, as well as extreme to exceptional drought, decreased.

Abnormal dryness and drought are currently affecting over 215 million people across the United States including Puerto Rico—about 69.2% of the population.