Welcome to the age of API weather insights

How EllisDon is bringing weather risk into the operating stack of a modern, data-native general contractor — successful pilots today, org wide API integration next.

1. The end of the “act of God” era

Construction’s relationship with weather has historically been one of resignation. Schedules slipped, claims were filed, contingencies were padded, and the line item read “act of God.” That model no longer holds.

The Global Temperature Anomaly has departed from the 1881–1910 baseline by margins that make historical averages an actively misleading planning input. The “average” weather day is a statistical artefact, and 93% of construction managers reported significant weather-related disruption in the past year alone.

EllisDon recognised this weather insights gap earlier than most. Through its ConTech Accelerator and the build-out of a sophisticated technology and innovation function spanning project controls, finance, risk, and insurance interfaces, EllisDon has positioned itself as one of the most data-native general contractors in North America. The partnership with EHAB — the team behind the WeatherWise platform — is a direct expression of that posture: weather is moving from narrative input to quantified data layer, with the dashboard pilot proving the value today and API integration mapped as the next step.

2. Modern construction selecting modern infrastructure

EHAB was selected from more than 165 submissions in the second cohort of the EllisDon and Impulse Partners ConTech Accelerator. From a final eight, EHAB became one of three companies accelerated across the EllisDon portfolio.

“What impressed us most about EHAB is its ability to connect weather and climate data directly to construction schedules. That linkage turns uncertainty into something teams can plan around rather than react to.”

— EllisDon Innovation Team

The selection criteria were not about novelty. They were about whether the technology could fit into EllisDon’s existing operating fabric — Oracle Primavera, Deltek Acumen, the company’s risk frameworks, its bid governance, its claims documentation, and its safety planning. WeatherWise was chosen because it could function as a shared weather data layer across all of those workstreams — starting with the dashboard, with API-level integration as the natural next step.

“We are currently piloting EHAB WeatherWise Technology on a select group of projects at EllisDon, and even at this early stage, the potential benefits are already becoming clear. Accurate prediction of adverse weather is fundamental to effective project planning, influencing risk assessments, schedule contingency strategies, safety planning, and budget allowances for temporary heat and winter protection. EHAB offers a promising path toward strengthening all of these areas.”

— Ali Vessali, Civil Eng, CM-Lean — VP, Corporate Planning and Scheduling, Construction Sciences, EllisDon

What sets EllisDon apart in EHAB’s customer base is the breadth of intent. The same weather data is being used to inform the schedule risk model, the EOT claims defence file, the insurance conversation, the bid contingency calculation, and field safety protocols. That horizontal reach — across technology, finance, planning, claims, and risk transfer — is what a modern construction business looks like.

“As climate volatility increases, tools like EHAB are becoming essential to protecting schedules, budgets, and safety on site.”

— EllisDon Innovation Team

3. The pilot in practice

The pilot is running today through the WeatherWise dashboard. EllisDon’s planning teams configure trade-specific weather rules, run probabilistic analyses against decades of historical data, and bring the resulting risk calendars into the bid, scheduling or QSRA workflow (depending on project risk appetite). The value is being proven on real projects with real schedules. The API integration that would automate this end-to-end is the next step under active assessment by EllisDon’s technology team.

Workflow today

• P6 schedule alignment. Weather-sensitive activities are flagged in Oracle Primavera P6 with activity codes. Planners use the WeatherWise dashboard to run probabilistic analyses against those activities and feed the resulting risk calendars into the schedule workflow.
• Weather Rules back-tested against 45+ years of data. Thresholds for wind, precipitation, temperature, and other variables are configured per trade and per region inside the dashboard, then validated against decades of historical observations from over 17,500 weather stations and 60 satellite sources.
• Risk calendars feeding Acumen Risk. Probabilistic risk calendars from WeatherWise are brought into Deltek Acumen Risk for Monte Carlo simulation, exposing weather-driven critical-path risk that traditional QSRA misses.
• Audit-ready outputs aligned to NEC, FIDIC, and JCT. As-built weather data is captured continuously and made available through the dashboard, providing defensible evidence for Extension of Time submissions and compensation events under any major contract framework.

“By leveraging a vast global weather dataset and powerful analytical and predictive capabilities, EHAB can help us build project plans and schedules that are truly weather-risk-aware. Through the pilot, we are seeing how earlier visibility into weather-related risks could support more informed decision-making and more resilient planning.”

— Ali Vessali, EllisDon

4. Standardising risk across a continental portfolio

EllisDon delivers projects from Pacific coastal climates to Arctic conditions, across every major Canadian climate zone and into the United States. Without a common empirical framework, “regional contingency” becomes a function of who built the schedule and what they remember about last winter.

WeatherWise resolves that inconsistency by anchoring contingency to data rather than memory.

“Another promising outcome is the ability to standardize our regional approach to weather contingencies. EHAB’s data-driven framework could help us establish consistent, evidence-based buffers and contingency strategies across different climates and geographies, improving both internal alignment and communication with stakeholders.”

— Ali Vessali, EllisDon

This standardisation is what allows a global enterprise to defend its numbers — internally to executive review, and externally to clients, lenders, and insurers. It is also what allows the same risk framework to feed downstream into bid contingency, insurance placement, and claims posture.

5. The claims and contractual layer

The Extension of Time claim is where weather data either earns its keep or fails the project. Anecdote is not evidence. Regional averages are not site-specific evidence. What the contract requires is as-built site weather, benchmarked against an empirical baseline, in a format that survives scrutiny.

“We also see strong potential in EHAB’s ability to support Extension of Time (EOT) claims related to the lost productivity due to the adverse weather conditions. By comparing as-built weather data against long-term regional averages, the platform could help substantiate claims where adverse conditions exceed normal expectations, providing clarity, transparency, and stronger documentation.”

— Ali Vessali, EllisDon

This is where WeatherWise meets EllisDon’s broader data discipline. The same weather signal that drove the original schedule contingency now drives the EOT submission, with the audit trail intact from baseline to as-built. Planning, claims, and finance all read from the same record.

6. The safety and operations layer

Schedule and claims are the visible outputs. Safety is the underlying obligation. Heat stress, wind on cranes, freeze-thaw cycles on concrete pours — these translate directly into worker risk and quality liability long before they show up as schedule slip.

“The ability to run proactive weather-risk analyses is emerging as a valuable capability. With early insights into potential adverse conditions, our project teams can better prepare safety measures, adjust sequencing, and plan for continuity of progress before issues arise.”

— Ali Vessali, EllisDon

Proactive sequencing is the operational dividend of probabilistic planning. The schedule is not just defended after the fact — it is reshaped before the weather arrives.

7. The road ahead: from dashboard to API

The dashboard pilot is doing the job today — demonstrating that probabilistic, evidence-based weather risk planning produces tangible benefits across schedule, claims, and safety. What it doesn’t yet do is run automatically. That is the next chapter, and it’s the obvious one.

EllisDon’s technology and innovation function is now assessing the WeatherWise API as the route to embed weather data directly into the systems planners and project teams already use — from Oracle Primavera and Deltek Acumen through to bid management, project controls dashboards, BI layers, and the safety and insurance interfaces that sit alongside delivery. The objective over time is a weather data layer that any system in the EllisDon stack can consume on demand: standardised, programmatic, and continuously refreshed.

This is the trajectory that distinguishes a modern, data-native general contractor. Most of the industry is still asking whether weather data belongs in the planning process. EllisDon has answered that question through the pilot — and is now asking the next one: how deep should the integration go.

Globally analogous infrastructure projects on the WeatherWise platform have demonstrated outcomes including 27 days saved and approximately £59 million (~$105 million CAD) in value preserved on a single job. The EllisDon pilot is positioned to translate those benchmarks into the Canadian context across an expanding portfolio.

“While we are still in the pilot phase, EHAB WeatherWise Technology is already demonstrating meaningful value. We look forward to exploring its full potential as we continue evaluating its fit across our broader project portfolio at EllisDon.”

— Ali Vessali, Civil Eng, CM-Lean — VP, Corporate Planning and Scheduling, Construction Sciences, EllisDon

8. The bigger picture

EllisDon is what a modern construction business looks like: a tech-forward enterprise that treats data as infrastructure and is building the muscle to consume it horizontally across project controls, finance, insurance, and field operations. WeatherWise is becoming the weather data layer in that stack — probabilistic, evidence-based, audit-ready, and trending toward fully programmatic.

The era of the weather-aware master schedule has arrived. The next chapter — the API-native general contractor — is being written.

WeatherWise by EHAB · Weather risk intelligence for modern infrastructure delivery · ehab.co