Understanding Weather Delay Percentage
How we calculate. Weather % = weather delay days ÷ planned workdays × 100. The form uses the same arithmetic as the worked examples on this page. See our methodology and accuracy policy.
Real-world scenario: A typical Weather Delay Percentage case uses weather delay days 6 and planned workdays 60. Enter the same figures below to reproduce the worked path.
What is Weather Delay Percentage?
A schedule-risk KPI for outdoor work. Align delay day definitions with the contract’s weather clause.
- Same calendar basis
- Define a weather day
- Segment by trade
The Formula
Worked Example
Common Use Cases
- Schedule updates: weather impact
- Claims support: delay documentation
- Seasonal planning: contingency days
Pro Tips
- Log concurrent delays separately
- Match contract weather thresholds
- Don’t double-count weekends
Limitations: Weather Delay Percentage results are educational construction planning aids—not engineering, safety, legal, or cost-estimating advice. Confirm definitions with your project controls, safety, and contract documents. For earned-value SPI/CPI see the Professional hub.
FAQ
Calendar days or workdays?
This form uses planned workdays in the denominator—keep weather days on the same basis.
What if planned workdays is 0?
Weather delay % is undefined—enter a positive planned workday count.
Authoritative References
For construction project controls and safety rate concepts, consult: