unpredictable

adjective

un·​pre·​dict·​able ˌən-pri-ˈdik-tə-bəl 

: not predictable: such as

a

: not able to be known or declared in advance

unpredictable weather

b

: tending to behave in ways that cannot be predicted

an unpredictable boss

unpredictably

ˌən-pri-ˈdik-tə-blē 

adverb

changes that occur unpredictably

unpredictability

ˌən-pri-ˌdik-tə-ˈbi-lə-tē 

noun

the unpredictability of the weather

Synonyms of unpredictable

• volatile
• changeful
• unstable

Examples of unpredictable in a Sentence

unpredictable spring weather that makes it really hard to know what to wear

Recent Examples on the Web

However, domestic flights remain limited, expensive and unpredictable, while ferry services are irregular and the maritime sector struggles with aging fleets and weak incentives to improve. — Emese MacZko, Forbes.com, 1 Aug. 2026

Uneven surfaces and unpredictable weather, however, are better suited to more durable materials such as rubber or water-resistant leather. — Alison Syrett Cleary, InStyle, 1 Aug. 2026

Even while navigating a challenging economic landscape—marked by fluctuating input costs, unpredictable weather and shifting market dynamics—growers are choosing to formalize and voluntarily provide data on their sustainability practices. — Sj Studio, Footwear News, 31 July 2026

And with these CDs being FDIC-insured up to $250,000 per account, there's an additional layer of protection to account for here that can make these accounts worth serious exploration in today's unpredictable financial climate. — Matt Richardson, CBS News, 31 July 2026

Word History

First Known Use

1840, in the meaning defined above

Rhymes for unpredictable

• indictable
• predictable

Kids Definition

unpredictable

adjective

un·​pre·​dict·​able

ˌən-pri-ˈdik-tə-bəl

: not predictable

unpredictability

-ˌdik-tə-ˈbil-ət-ē

noun

unpredictably

-ˈdik-tə-blē

adverb