Weather is the most common cause of schedule delay in construction and the most frequently disputed. Every outdoor project will lose days to rain, snow, extreme heat, high winds, or frozen ground—the question is how many days, whether those days entitle the contractor to a time extension, whether they also entitle the contractor to additional compensation, and how make-up work is scheduled to recover lost time. The answers depend on the contract language, the baseline weather assumptions, and the quality of your daily tracking.
Effective weather delay management starts before the first shovel hits the ground: establishing baseline expectations in the contract, setting up daily weather tracking systems, and building float into the schedule for expected weather events. This guide covers the legal framework, practical tracking methods, recovery strategies, and the cost impacts that weather delays impose beyond just lost calendar days.
Excusable vs. Compensable Delays
Contract law classifies delays into three categories. Excusable, non-compensable delays entitle the contractor to a time extension (more days to finish) but not additional money. Most weather delays fall here—the contractor gets extra calendar days but absorbs the cost of idle labor, equipment, and extended overhead. Excusable, compensable delays entitle the contractor to both time and money, but weather-related compensable delays are rare and typically require proving the weather was "unusually severe" beyond what was reasonably foreseeable. Non-excusable delays are the contractor's fault and receive neither time nor money.
The key distinction for weather is "foreseeable vs. unforeseeable." A contract for exterior work in Chicago from November to March should anticipate some freezing days—those are foreseeable and typically non-compensable (the contractor should have built them into the bid schedule). A freak ice storm in June, however, may qualify as an excusable and potentially compensable delay because it was not reasonably foreseeable. The baseline for "foreseeable" is usually the 10-year or 30-year weather average for the project location and season.
Federal contracts (FAR 52.249-10, Default clause) explicitly allow time extensions for "unusually severe weather." The contracting officer compares actual weather events to historical averages (often using the National Weather Service 30-year normal data) and grants additional days only for weather that exceeds the baseline. For example, if the historical average shows 5 rainy days in April for the project county and the actual count is 9, the contractor may receive a 4-day time extension. Only the excess over the anticipated baseline qualifies.
Rain Day & Weather Delay Tracker
Track weather delay days against contract allowance, project schedule impact, and compare delay costs versus Saturday make-up work with regional precipitation benchmarks.
Weather Day Tracking Methods
Accurate daily weather tracking is essential for supporting time extension claims. At minimum, maintain a daily log that records: temperature (high/low), precipitation (type and amount), wind speed, ground conditions (frozen, muddy, dry), and the impact on each trade or activity. "Rained all day" is not sufficient documentation. "0.75 inches of rain between 6 AM and 2 PM; site access roads impassable; concrete pour postponed; iron crew stood down at 10 AM due to wet steel and lightning within 5 miles" is.
The best tracking method combines your daily superintendent report with data from a nearby NWS weather station. Weather station data provides objective, third-party verification of conditions that is difficult to dispute in a claim. Identify the nearest ASOS (Automated Surface Observing System) station to your site—most airports have one—and record the station ID in your project files. You can pull historical daily data from the NWS Climate Data Online archive at any time, but contemporaneous daily logging from the job site is stronger evidence because it documents the actual impact on work.
Define "weather day" criteria in your project-specific quality/safety plan: a full weather day (no productive work possible), a partial weather day (some activities impacted but others proceed), and a non-impact day (weather present but work continues normally). A light drizzle may stop exterior painting but not interior electrical rough-in. Only days where weather prevents critical-path work should count toward time extension requests. Document which specific activities were impacted and why, not just that it rained.
Make-Up Scheduling Strategies
Saturday work: The most common recovery method. Adding a 6th workday at straight time (if the CBA allows) or at overtime rates recovers 8–10 hours per week. On a 50-day delay exposure, working 5 Saturdays can recover 2–3 calendar weeks. The cost is overtime premium (if applicable), supervision for the extra day, and fatigue-related productivity loss if sustained more than 3–4 weeks. Most union agreements allow Saturday work at 1.5× rates; some allow it at straight time with advance notice.
Extended shifts: Moving from 8-hour to 10-hour days adds 10 hours/week (2 hours × 5 days). This is often more cost-effective than Saturday work because the incremental cost is only the overtime premium on 2 hours/day versus 8 hours on Saturday, and crew mobilization happens only once per day instead of an extra time on Saturday. However, sustained 10-hour days for more than 4 weeks produce measurable productivity loss (see the six productivity factors). Use 10-hour shifts for short-term recovery (2–4 weeks) and revert to normal schedules once the float is recovered.
Crew stacking: Adding additional crews or increasing crew sizes to accelerate production. This works when the work can be physically subdivided (e.g., different floors, different systems, different areas of a site) but backfires when crews are stacked into the same work area, causing congestion losses that offset the additional labor. Crew stacking is most effective on projects with linear or repetitive work (pipeline, roadway, multi-building sites) and least effective on single-space projects (one building, one room). Estimate the congestion factor before committing to a stacking strategy.
Overtime Cost Projection Tool
Analyze the true cost of overtime including hidden costs like turnover, fatigue incidents, FICA, and workers comp. Compares OT strategy vs hiring additional staff with break-even analysis.
Cost Impact of Weather Delays
The direct cost of a weather delay day includes standby labor (workers report to the site, cannot work, may receive show-up pay per the CBA—typically 2–4 hours), idle equipment rental (you pay the daily/monthly rate whether the crane operates or not), and extended general conditions (superintendent, project manager, trailer, utilities, insurance—prorated at $2,000–$10,000 per day depending on project size). These are real, measurable costs that add up quickly.
Indirect costs are harder to quantify but often larger: subcontractor delay claims (downstream trades waiting for you to finish), liquidated damages if the project misses its completion milestone, lost revenue for the owner if the facility cannot open on time (which becomes the contractor's problem if the delay is deemed non-excusable), and opportunity cost of tying up your workforce and equipment on a stalled project instead of starting the next one. On a $20 million commercial project, extended general conditions alone run $5,000–$8,000 per calendar day, and 20 weather delay days produce $100,000–$160,000 in overhead cost before any recovery efforts.
Build weather contingency into bid pricing, not just the schedule. If the 30-year average shows 15 weather-impact days for your project's location and duration, price those 15 days of extended general conditions into the bid. The schedule should show the impact as float or as explicitly calendared non-work days. Trying to absorb weather costs from profit margin is a recipe for losses on any project longer than 3 months.
Per Diem & Travel Pay Calculator
Calculate per diem, lodging, mileage, and mobilization costs with GSA rate tiers, first/last day 75% rule, meal deductions, and IRS mileage rates. Includes rate lookup guidance.
Contract Provisions and Documentation
The time to negotiate weather delay provisions is during contract formation, not after delays occur. Key contract provisions to review and negotiate: the definition of a "weather day" (full day lost vs. partial impact), the baseline for "anticipated" weather (30-year NWS average vs. 10-year vs. project-specific), the notice requirement for claiming weather delays (typically 5–10 days), whether the contractor gets time only or time and money, and the method for calculating additional compensation if compensable.
On private contracts, weather provisions vary widely. Some contracts give the contractor automatic time extensions for any day with measurable precipitation. Others require proof that weather prevented critical-path work. The most onerous contracts treat all weather as the contractor's risk with no time extensions. If you are bidding a 12-month outdoor project with zero weather days in the contract schedule, either add weather contingency to your price or negotiate a weather clause—do not assume the owner will be reasonable after the fact.
Force majeure clauses may cover extreme weather events (hurricanes, tornadoes, record-breaking cold) that exceed anything in the historical record. Standard force majeure language typically requires the event to be beyond the parties' control, not reasonably foreseeable, and impossible (not just difficult or expensive) to work through. A Category 4 hurricane qualifies. A heavy rainstorm in spring probably does not. Review force majeure language carefully and understand the notice requirements, which are often strict (written notice within 48–72 hours of the event).