Ideal Temperatures in Refrigerated Containers
There is no single temperature for a refrigerated container: every fresh product has its own. Bananas travel at 13.3 °C (56 °F), green Hass avocados between 5 and 7 °C (41 to 45 °F), cut flowers between 1 and 2 °C (34 to 36 °F) and dairy between 0 and 4 °C (32 to 39 °F). Setting one degree too high or too low is not a detail: it decides whether the cargo arrives sellable or arrives as a claim.
This article focuses on fresh produce, the kind that keeps respiring inside the container. If your cargo travels frozen, the range and the logic are different, and we cover them in
Temperature table by fruit and vegetable
Relative humidity matters as much as the degree: with low humidity the product dehydrates and loses weight, and with excessive humidity mold appears.
| Product | Temperature | Relative humidity |
|---|---|---|
| Green bananas | 13.3 to 13.9 °C (56 to 57 °F) | 90 to 95% |
| Green Hass avocado | 5 to 7 °C (41 to 45 °F) | 85 to 90% |
| Mango | 10 to 13 °C (50 to 55 °F) | 85 to 90% |
| Orange and mandarin | 5 to 7 °C (41 to 45 °F) | 85 to 90% |
| Lemon and lime | 10 to 13 °C (50 to 55 °F) | 85 to 90% |
| Table grapes | -0.5 to 0 °C (31 to 32 °F) | 90 to 95% |
| Strawberries | 0 to 1 °C (32 to 34 °F) | 90 to 95% |
| Tomato | 10 to 13 °C (50 to 55 °F) | 90 to 95% |
| Bell pepper | 7 to 10 °C (45 to 50 °F) | 90 to 95% |
| Carrot | 0 °C (32 °F) | 95 to 100% |
| Onion and garlic | 0 °C (32 °F) | 65 to 70% |
| Sweet potato | 13 to 15 °C (55 to 59 °F) | 85 to 90% |
The figures correspond to reference storage conditions collected in postharvest manuals such as the USDA Agriculture Handbook 66. The buyer or the destination market may require a different value within the range, and that requirement overrides any general table.
Other refrigerated cargo
| Cargo | Temperature |
|---|---|
| Cut flowers, ocean transport | 1 to 2 °C (34 to 36 °F) |
| Cut flowers, road transport | 2 to 4 °C (36 to 39 °F) |
| Fresh dairy | 0 to 4 °C (32 to 39 °F) |
| Fresh meat and fish | 0 to 2 °C (32 to 36 °F) |
| Vaccines and biologicals | +2 to +8 °C (36 to 46 °F) |
| Refrigerated food, Colombian health requirement | No higher than 4 °C (39 °F), with a tolerance of ±2 °C |
That last figure comes from Resolution 2674 of 2013, the regulation that sets the health requirements for food in Colombia, enforced by the INVIMA. It establishes refrigeration at no more than 4 °C ±2 °C, freezing at -18 °C (0 °F) or lower, and requires control, logging and calibration of measuring equipment.
Colombian export fruit
Bananas are the most demanding case and the one that moves the most volume. They travel green, at around 13.3 °C (56 °F), and on long routes they are shipped in controlled-atmosphere containers with about 3% oxygen and 4 to 5% carbon dioxide. Lowering the oxygen slows the fruit's respiration and delays ripening enough to reach destinations that were once unviable by sea.
Hass avocados are shipped green at 5 to 7 °C (41 to 45 °F). Published ranges go from 2 to 13 °C (36 to 55 °F) depending on ripeness and the length of the trip: the longer the transit, the colder within the safe range. They are usually accompanied by modified atmosphere with liners and ethylene filters, because the avocado itself emits the gas that accelerates its ripening. For the exporter, beyond temperature, dry matter at harvest and certification by the ICA (Colombia's agricultural agency) also count.
Citrus falls into two groups: oranges and mandarins tolerate cold, between 5 and 7 °C (41 to 45 °F), while lemons and Tahiti limes need a warmer range, 10 to 13 °C (50 to 55 °F). Bringing them down to orange temperature causes pitting and staining of the peel.
Cut flowers are the most time-sensitive product. Every hour out of range shortens vase life. In an ocean container they are kept between 1 and 2 °C (34 to 36 °F), and by truck between 2 and 4 °C (36 to 39 °F); the stems are cooled practically on the farm and the chain cannot be interrupted until the destination.
In Colombia, these cargoes leave mainly through Cartagena, Buenaventura and Santa Marta, whose yards have dedicated reefer plugs so the container is never left without power while waiting to be loaded.
Chilling injury and ethylene
Cooling more is not safer. Every species has a threshold below which it suffers chilling injury: internal browning, pitting of the peel, inability to ripen and off-flavors. Mango, tomato, sweet potato and thin-skinned citrus are especially sensitive and must not be taken below their threshold, not even for a few hours.
The other factor is ethylene. Many fruits emit it as they ripen, and that same gas accelerates the ripening of the rest of the cargo. That is why reefers have an adjustable fresh-air vent and, in demanding operations, absorbent filters. Products that emit ethylene must never be mixed in the same container with products that are sensitive to it.
How to secure the temperature in the container
- Pre-cool before loading. The container maintains temperature; it does not cool. The fruit must go in already at its transport temperature.
- Stow leaving air channels. With fresh produce, air must circulate between the boxes to remove the heat of respiration. With frozen goods, by contrast, the load is stowed tightly.
- Do not exceed the red line. Blocking the return air makes the unit read a temperature the cargo does not have.
- Look after the T-bar floor. The floor channels are the path the cold air enters through. If they are blocked, the bottom of the container warms up.
- Log the full curve. Data loggers at the critical points and, when the value of the cargo justifies it, remote monitoring with alarms.
- Secure power on every leg. Vessel, port yard, genset on the road or three-phase supply at the plant. A single window without a connection is enough to break the chain.
Documentary and customs compliance at destination is a separate matter; what matters here is that the temperature curve arrives clean.
To understand the equipment from the inside, read
Frequently asked questions
At what temperature do export bananas travel?
Between 13.3 and 13.9 °C (56 to 57 °F). On long routes this is combined with a controlled atmosphere of about 3% oxygen and 4 to 5% carbon dioxide to delay ripening during the voyage.
What happens if I set a lower temperature to be safe?
The cargo is damaged. Tropical fruits such as mango, banana or lime suffer chilling injury below their threshold, with browning, pitting and loss of the ability to ripen. The damage often only shows at destination, when there is no longer any remedy.
Can products be mixed in the same container?
Only if they share the same temperature range, relative humidity and behavior towards ethylene. Combining onions with fruit, or an ethylene emitter with a sensitive product, ruins one of the two lots even if the temperature is correct.
Does green coffee need a refrigerated container?
No. Green coffee is normally exported in a dry or ventilated container, with liners and humidity control between 10 and 12%. Its enemy is condensation, not heat, and a reefer offers no advantage over good humidity management.
Who sets the final temperature of the cargo?
The buyer or the authority of the destination market. Reference tables are for sizing and planning, but the shipping instruction is what gets programmed into the unit and what is audited afterwards in the temperature curve.