The last time it was this dry in January, there were barely more than 500 people in San Diego. The year was 1850, and only a quarter-inch of rain had fallen in six months. It made the region ripe for wildfire — but that wasn’t much of a concern. The city’s population was clustered along the coast, far from the backcountry, where most fires burned.

An uptick in Santa Ana winds Wednesday afternoon through Thursday, combined with critically dry vegetation and low humidity, will result in elevated to locally critical fire weather conditions in County through late Thursday.

Just a few years after the ozone hole was detected via satellite, the industrialized nations of the world, meeting in Montreal in 1987, adopted what is known as the Montreal Protocol.

Santa Ana winds finally delivered a big, direct hit on San Diego County Tuesday, gusting as high as 102 mph in the backcountry where a touch of long-overdue rain could arrive this weekend.

A critical fire threat will continue across County as Santa Ana winds and dry conditions persist through early Friday, according to the National Weather Service.