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

As the episode makes clear, fishing this far north comes with brutal conditions, including shallow waters, towering waves and subzero temperatures. —Deirdre Durkan, PEOPLE, 7 May 2026

Crews worked in subzero temperatures to put out the blaze, but despite their best efforts, the building was a total loss. —Christopher Derose, CBS News, 8 Apr. 2026

For many attendees, the event offered welcome relief and an excuse for a family outing after a harsh winter marked by subzero temperatures, nightly Russian drone and missile attacks and crippling power cuts. —Derek Gatopoulos, Chicago Tribune, 6 Apr. 2026

That’s partly because heat pumps work by extracting heat from outdoor air, compressing it and piping it indoors, a thermal magic trick that’s harder to perform in places with subzero winters. —Ben Christopher, Los Angeles Times, 1 Mar. 2026

Word History

First Known Use

1887, in the meaning defined at sense 1

Rhymes for subzero

• biro
• spiro
• zero
• superhero

Kids Definition

subzero

adjective

sub·​ze·​ro

ˌsəb-ˈzē-rō

: being or marked by temperature below zero