What is reefer container monitoring?

Reefer container monitoring is the continuous recording of internal temperature, humidity, and unit status via onboard data loggers and, increasingly, remote satellite or cellular telemetry that transmits readings during ocean transit, allowing carriers and shippers to track cargo conditions in near real time rather than only at delivery. Independent dispatch data indicates that reefer units awaiting plug-in at West Coast terminals after discharge experience power-gap windows most commonly in the 1-4 hour range during normal operations, and field-level tracking shows these windows can extend significantly during high-volume periods when dedicated reefer plug racks are at capacity.

Reefer Container Monitoring: How Temperature Tracking Works

Cost structure / standard tiers

Reefer cargo carries monitoring, plug-in, and excursion-related costs distinct from dry container handling.

Item	Basis	Typical Range / Note
Reefer plug-in fee (terminal)	Per container/day	$50-150/day
Remote monitoring/telemetry fee	Per container, per voyage	$50-200, often carrier- or provider-billed
Reefer download / data logger report	Per request	Often included with carrier service; turnaround varies
Temperature excursion claim investigation	Per incident	Variable; depends on cargo value and excursion duration
Reefer yard storage (after free time)	Per day	Often a premium over standard demurrage, varies by terminal

Sustained deviation between set point (the configured target) and actual return-air/supply-air readings is the primary indicator used to assess whether an excursion occurred and for how long.

Risk mitigation / operational guidance

For temperature-sensitive cargo, request the reefer download (data logger report) for every shipment as a standing process step, since this time-stamped record is often the deciding factor in cargo claims if spoilage is suspected. Confirm reefer plug rack availability at the destination terminal before vessel arrival during high-volume periods, since plug-in delays directly translate to set point/actual temperature drift. Track set point versus actual readings against the cargo's tolerance range rather than against a single pass/fail threshold — brief variances from door openings during inspection are normal, but sustained deviations warrant investigation. For regulated commodities (certain pharmaceuticals, produce), confirm the cold chain documentation retention requirements with the relevant regulatory body before transit, and build the reefer download request into the standard arrival checklist rather than requesting it only when a problem is suspected.