An idle Snowflake warehouse is running but processing no query. It continues to consume credits until it stops.
WAREHOUSE_METERING_HISTORY reports credits consumed by warehouse and hour. QUERY_HISTORY reports query activity. Comparing the two identifies hours in which a warehouse consumed credits without processing statements.
Idle time can occur between scheduled jobs, after an interactive session ends, or when a warehouse is larger than the workload requires. A large warehouse makes each idle interval more expensive because its credit rate is higher.
Separate workloads with different schedules so each warehouse can match its own demand. Choose an idle-time limit that fits the gap between queries and the latency required when a warehouse starts again. The 60-second minimum on each start makes repeated short runs more expensive, so the setting must be evaluated with query frequency.
Resource monitors can alert on or stop warehouse usage after a credit threshold. A monthly comparison of idle credits, execution credits, and queue time shows whether a change reduced cost or moved it elsewhere.
Snowflake documents warehouse activity and warehouse metering history.