Term

BECMG

Daniel MarkFounder & Editor, Aviatopia
Published Mar 1, 2026Updated Mar 1, 20261 min read

Becoming — a TAF change indicator meaning conditions are expected to gradually transition to a new state within a specified time window.

aviation-glossary

Quick Facts

Type
TAF Change Group
Also Known As
BECMG
Used By
Pilots, Dispatchers

Definition#

BECMG (Becoming) is a change group used in TAFs to indicate that weather conditions will gradually change from one state to another over a defined period (typically 2–4 hours).

Why It Matters Operationally#

BECMG groups inform dispatchers and pilots when conditions are expected to deteriorate or improve, directly affecting alternate planning, fuel reserves, and go/no-go decisions.

Example#

BECMG 1216/1218 3SM BR OVC010

Means: between 1600Z and 1800Z on the 12th, conditions will become 3 statute miles visibility in mist with overcast at 1,000 feet.

See Also

Used in