COLUMBUS, Ohio (WCMH) — The description of omicron COVID-19’s spread through Ohio as a wave is apt, both in how it went up and down statewide and how it moved geographically through the state.

After hitting a daily peak in cases in early January, coronavirus cases driven by the omicron variant are trending down in every Ohio county. But they are not trending down equally everywhere.

Ohio’s omicron wave first hit northern counties, chiefly the Cleveland and Akron areas. It then moved south, disrupting central Ohio and then southern Ohio. Because the north was the first to see a big spike in omicron cases, it’s the first to see a tremendous reduction in cases.

An NBC4 analysis of Ohio Department of Health data as of Tuesday illustrates this wave, finding that northern Ohio is improving the most, followed by the central and southern regions.

Ranking counties 1-88 by onset cases per 1,000 people over the past two weeks (Feb. 1-14), the map below shows how the fastest-improving counties are in the north and the slowest improving counties are toward the south.

The map divides the ranked counties into fourths. The lightest-colored counties, ranked 1-22, are all north of Columbus and include every county along the Lake Erie shoreline.

Counties ranked 23-44 and 45-66 in February cases per capita are a mix of places mostly in the central third of Ohio, including 30th-ranked Franklin County. These middle categories also span most of western Ohio, where infections and hospitalizations were late to improve in cities like Dayton, Findlay and Lima.

Finally, COVID-19 began improving in southern Ohio the latest of any region, as revealed by the map’s deep blue counties mostly south of Columbus.

A few counties buck the trend, including Union County, northwest of Columbus. At 5.46 cases per 1,000 residents over two weeks, Union is ranked 74th of 88 counties.

Two-week case rates range from 1.07 per 1,000 residents in first-ranked Holmes County to 14.93 per 1,000 in last-ranked Lawrence County, Ohio’s southernmost county.