Impact of climate risks on logistics: where SLAs break before the rain hits

Introduction

It's 2 PM on a Tuesday. The truck left the DC at 6 AM, the customer's receiving window is 6 PM, and a heavy rain alert just hit the coordinator's phone. From here, every decision costs money: hold the shipment, risk the route, pay for emergency freight, or call the customer and apologize.

The impact of climate risks on logistics almost never starts with the storm. It starts the moment the operation finds out about the problem too late to pick the cheapest way out.

In this article, you'll see where weather breaks SLAs, how to calculate what that costs your operation, and what separates companies that react to the event from those that decide days before it hits.

Why weather became an SLA variable

Two recent events in Brazil show that weather is no longer the exception. It now sets the pace, cost, and capacity of logistics operations.

Floods in Rio Grande do Sul (April and May 2024). Every transport mode in the state was hit, and the Porto Alegre airport stayed closed for about five months, with a gradual restart of operations. In the survey CNT conducted a year later, 193 cargo and passenger transport companies were interviewed, 133 of them operating in affected regions (CNT). Among companies with direct losses, 85.4% reported operational disruption. Meanwhile, 38.2% of those that estimated financial losses reported damages above R$ 1 million. And 16.5% still hadn't returned to normal operations.

Drought in the Amazon rivers (2023 and 2024). In October 2023, ships sat idle for weeks, unable to pass, and container traffic in Manaus dropped 85% compared to August. In 2024, even with floating piers in Itacoatiara, the drop was 55% in October and 41% in November compared to the July peak, according to a study by A&M Infra for Abac (Estadão Conteúdo). The same study estimates that a 2-meter draft restriction cuts capacity by 35% and raises unit cost by 63%.

The pattern repeats: the event is physical, but the damage is contractual. Deadlines missed, extra freight costs, inventory that has to be pulled forward, and customers waiting at the dock.

Weather Impact on Logistics SLA: Three Ways It Breaks

Weather breaks SLAs through three different paths, and each one requires a different response. Treating all of them as "delayed due to rain" hides where the real cost lives.

1. In-transit delay. The route gets blocked, speed drops, or the driver has to take a detour. The cargo exists and the customer exists, but the time between them grows.

2. Node unavailability. The DC, port, or terminal stops operating. Here, switching routes doesn't help, because the origin or destination point itself is closed.

3. Cascade effect. One day's backlog contaminates the days that follow. The SLA keeps breaking even after the weather clears, because the operation has to absorb two days' worth of volume in one.

The cost goes beyond the stoppage itself. In the CNT survey on the RS floods, 52.8% of transport companies with direct losses reported additional logistics expenses on top of the disruption itself.

What Weather Costs Your Operation

To move from perception to a real number, apply this formula to a recent event in your operation:

Event cost = (hours of disruption × cost per hour) + SLA penalties + emergency freight + cost of stockout

Most companies only see the first line item. Penalties, emergency freight, and lost sales from stockouts tend to show up in different cost centers, which is why climate risk looks smaller than it actually is.

Weather-Based Route Planning: From Fixed Routes to Decision Windows

The real gain from adaptive route planning isn't dodging the rain. It's buying time to choose the cheapest way out before that option disappears.

Compare the options across three decision windows. The table below is an illustrative scenario, not a guarantee of lead time: predictability depends on the type of event, the region, and the operation. Even with 72 hours' notice, there can still be uncertainty about where and how intensely rain will fall, especially with convective storms.

• 72 hours: move up pickup, switch modes, redistribute volume between DCs, renegotiate the customer window.
• 24 hours: change the route, adjust staff scheduling, give the customer some notice.
• 6 hours: hold the shipment or risk the route, pay emergency freight, apologize.

Each hour lost takes options off the table. At 6 hours, the decision stops being logistics and becomes crisis management.

The 2024 Manaus Drought Case

On June 20, 2024, Maersk warned the market that, based on ANA's river level gauges, there could be a draft restriction in Manaus starting mid-September, and recommended shipping ahead of schedule (Maersk). In July, the company confirmed a drought surcharge of USD 5,900 per dry container, applied to shipments priced from August onward. In a later update, the restriction date was moved up to September 1.

The warning came almost three months before the problem hit. Companies that treated it as a trigger for action had weeks to split reservations, move up shipments, and build up inventory. Those that treated it as just news found out the cost on the invoice.

In Rio Grande do Sul, 55.6% of affected transport companies made temporary route or logistics changes because of the floods (CNT). Changing routes is part of the response. What drives the cost is how much lead time that decision has.

Climate Risk in Distribution Centers: What Actually Shuts Them Down

A DC rarely stops because the structure failed. It stops because the truck can't get in, the dock floods, the power goes out, or staff can't leave home.

In the RS floods, 44.9% of transport companies with direct losses reported damage to their own infrastructure, like garages and warehouses (CNT). But physical damage is just the visible part. Disruption usually starts before it and ends well after.

So the right question isn't "how do we keep the DC running," it's "what makes the DC stop." Use this checklist to assess each site:

1. Access: do the roads leading to the DC flood or get blocked during heavy rain? Is there an alternate route?

2. Yard and docks: is drainage in the maneuvering area and docks sized for the region's design storms, defined by intensity-duration-frequency curves, rather than just the most recent major event?

3. Power: is there a generator or redundancy to keep WMS, refrigeration, and lighting running during outages?

4. People: can staff reach the DC when local public transit shuts down?

5. Sensitive inventory: are items that can't tolerate humidity or temperature swings stored in protected areas?

6. Structure: were the roof, gutters, and facade sized for the wind and rain the region sees today, not for conditions at the time the building was designed?

7. Shutdown threshold: does your team know at what point the DC stops operating, and how much advance notice is possible?

Item 7 is what separates maintenance from risk management. Without a defined threshold, every alert looks the same, and the team learns to ignore them.

The Most Common Mistake: Monitoring the Weather Instead of the Operation

Few companies monitor climate risk in a structured way. Even after the floods, 36.1% of affected transport companies in RS said they hadn't adopted any preparedness measures, and among those that did, only 16.3% included weather or logistics monitoring (CNT).

And those who do monitor often look in the wrong place: the weather forecast. It answers whether it's going to rain. It doesn't answer whether your route, your DC, or your contract is going to fail.

The Risk Lives in the Asset, Not the Weather

Two assets in the same place, under the same weather, can have very different exposures. An empty box truck and a loaded one react differently to crosswinds on a bridge. Two DCs in the same city can sit at different elevations within the same neighborhood.

Exposure lives in the asset: in the equipment, the layout, the site elevation, the contract. The same wind that's critical for one operation can be irrelevant for the one next door, which is why regional averages don't describe your specific stoppage.

The Most-Watched Variable Isn't Always the One That Explains the Stoppage

Every asset has a variable the market tracks out of habit, and it isn't necessarily the one that explains the stoppage. In ground logistics, rainfall in millimeters recorded in the city may matter less than accumulated rainfall in the watershed that floods access to your DC. Wind recorded at the nearest weather station may not be what's hitting the bridge where your operation actually stops.

The practical takeaway is simple. Your operation's stoppage history is one of the main inputs for setting risk thresholds, alongside technical safety limits, infrastructure characteristics, and modeling. And an absence of stoppages in the historical record doesn't mean an absence of risk.

What Maturity Level Is Your Operation At?

Climate risk management in logistics evolves across four levels. Each one changes the moment the decision gets made, and as a result, how much it costs.

1. Reactive. The operation finds out about the event as it happens. The decision gets made under pressure, with whatever options are left.

2. Generic forecasting. Someone tracks the weather forecast, but it isn't tied to any specific route, DC, or contract. Alerts come in, and the team doesn't know which ones matter.

3. Asset-level alerts. The company knows which routes and DCs are sensitive to which conditions. The alert already comes with the name of the affected asset attached.

4. Early decision-making. The operation has its own thresholds, calibrated against stoppage history and technical criteria, with a protocol for what to do when each one is hit. The decision happens days before the event.

If you recognized your operation in levels 1 or 2, you're not alone, and you're paying for it in penalties, emergency freight, and downtime hours that nobody's adding up today.

Find out where your operation breaks before the next storm hits. In our climate exposure assessment, we cross-reference the stoppage history of your critical routes and DCs with environmental data and show you which conditions actually stop your operation. Request a free exposure assessment!

Conclusion: Same Rain, Different Tuesday

Go back to the opening scene. Now the alert arrived the Saturday before, already flagged with the affected route and the threshold that typically stops that stretch. On Monday, pickup was moved up, the customer got a new window, and the truck took a different road.

On Tuesday, it rained just the same. The difference is nobody had to apologize.

The impact of climate risks on logistics depends as much on the events themselves as on each operation's exposure and preparedness. What you control is how much advance notice your operation gets and whether it knows what to do with that information.

Start by mapping your exposure. In an assessment that requires no system integration in the first step, we identify the routes and DCs where your operation concentrates the most risk, and the conditions that actually stop them. 

Frequently Asked Questions

How does weather affect delivery times?

In three ways: delaying transit (blocked or slower routes), stopping network nodes (DCs, ports, and terminals), and creating backlog that keeps delaying deliveries even after the weather clears. The third effect is the hardest to see and the one that does the most damage to monthly SLA performance.

What weather events impact logistics most in Brazil?

Heavy rain and flooding, which block highways and flood facilities, and droughts, which restrict navigation on rivers like those in the Amazon. Strong winds and rough seas also shut down port operations. How much each one matters depends on the region and the type of asset.

Can weather-related logistics disruptions be predicted?

In most cases, you can estimate the probability of disruption, with lead times that vary by event type: weeks or months for droughts, a few days for large-scale rain systems, and just hours for isolated storms. Weather forecasting shows the conditions expected in the atmosphere and at sea. Combined with asset exposure, operational thresholds, and stoppage history, it helps estimate the chance of impact, always with some uncertainty tied to the forecast itself and to the operation's response.

How do you build climate risk into SLA contracts?

One approach is to define in the contract which weather conditions qualify as an exception, using objective criteria and a data source agreed on by both parties. This reduces disputes over penalties and gives the operator an incentive to notify the customer ahead of time. Specific terms should be reviewed by each company's legal team.

What is weather-based route planning?

It's route planning that factors in forecasted environmental conditions for each leg, not just distance, cost, and the customer's delivery window. The goal is to make the call to change route, mode, or timing with enough lead time for it to still be the cheap option.

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