subzero

adjective

sub·​ze·​ro ˌsəb-ˈzē-(ˌ)rō 

-ˈzir-(ˌ)ō

variants or sub-zero

1

: registering less than zero on some scale (especially the Fahrenheit scale)

subzero temperatures

2

: characterized by or suitable for subzero temperatures

subzero winters

sub-zero snow boots

Here the altitude was almost a mile and a half above sea level and there was already hard frost in the mornings. With the first storm, the mornings would be subzero.

—Tony Hillerman

Examples of subzero in a Sentence

Recent Examples on the Web

In what’s been called a risky, daring, and heroic mission, a Royal New Zealand Air Force crew flew 2,400 miles in 20 hours in subzero temperatures and total polar darkness to evacuate three American scientists at the McMurdo research station in Antarctica on Aug. 5. —George Petras, USA Today, 9 Aug. 2025

Some places in Cincinnati and Northern Kentucky will get subzero wind chill temperatures and anyone who spends too much time outside may be at risk for frostnip, frostbite and hyperthermia. —Jolene Almendarez, The Enquirer, 2 July 2025

Though no part of Texas is expected to reach subzero temperatures, the latest forecast suggests some will come dangerously close, with parts of the Panhandle dropping as low as 1 degree. —Brandi D. Addison, Austin American Statesman, 2 July 2025

Wind chills ranging from -30 to -60 degrees Fahrenheit are forecast to persist for several days across the northern Plains, and subzero wind chills are also expected to reach as far south as Texas, Arkansas, and western parts of Tennessee and Kentucky. —Josh Hammer, Newsweek, 17 Feb. 2025

Word History

First Known Use

1887, in the meaning defined at sense 1

Rhymes for subzero

• nonzero
• biro
• spiro
• zero
• superhero

Kids Definition

subzero

adjective

sub·​ze·​ro

ˌsəb-ˈzē-rō

: being or marked by temperature below zero