How to Document a Weather Delay Claim

Most weather delay claims are not denied because the weather was fine. They are denied because the paperwork could not prove the weather was abnormal, that the day was genuinely unworkable, or that notice went out on time. Here is what actually holds up.

The three things every claim must prove

Whatever your contract says, a weather delay claim stands on three legs. Knock out any one and the claim fails:

1. The weather was abnormal. Not "it rained a lot" — measurably more than the historical norm for that location and month. This is the leg most subs cannot support, because it requires baseline data they do not have.
2. The work was actually impacted. The affected activity was scheduled, on the critical path, and weather-sensitive. Rain on a week you were not pouring is not a claim.
3. Notice was timely. Sent in writing, inside the contract's window, in the contract's required format.

Step 1: Establish the baseline before you argue about the weather

"Abnormal" is a comparison, and you cannot make a comparison without a reference. The reference is a historical average for the specific jobsite — typically 10 years of daily precipitation from the nearest official station, aggregated by month.

This is why experienced estimators attach an Anticipated Weather Exhibit at bid time. It fixes the baseline in writing before anyone has an incentive to argue about it. If you did not do that, you can still build the baseline retroactively from public NOAA records — but expect the GC to scrutinize it harder.

Step 2: Prove the day was unworkable, not just wet

This is where most claims get thin. A GC's standard response is: "It only rained 0.4 inches on Tuesday — why weren't you working Thursday?" You need an answer that is technical, not anecdotal.

The honest answer is usually soil. Rainfall stops work for a day; the ground keeps it stopped for three. Clay with poor drainage can hold a site down for days after the sky clears, while sand may be workable the same afternoon. If your documentation only tracks rainfall, you are silently conceding every drying day.

See how long soil takes to dry after rain for the mechanics of why the ground, not the forecast, sets your schedule.

Step 3: Keep the daily log that wins the argument

Each claimed day needs a line that answers: what was scheduled, what stopped it, and who was standing around.

• Date and measured precipitation (with the station identified)
• Scheduled activity and whether it was on the critical path
• Site condition — standing water, rutting, equipment sinking, unable to compact
• Crew and equipment idled — headcount and hours, because this is the damages number
• Photos with timestamps — supporting, never primary

Step 4: Send notice inside the window

Under AIA A201, that is 21 days from when you became aware of the delay. Other contracts are shorter. This is a hard deadline and it kills more good claims than bad weather ever did. Send it in writing, in the format the contract names, to the person the contract names — even if you do not yet have the full analysis. Notice preserves the right; the evidence can follow.

See our plain-English walkthrough of AIA A201 §8.3 for the exact language.

The five mistakes that sink claims

1. No baseline. You cannot prove "abnormal" without one.
2. Late notice. Fatal regardless of merit.
3. Claiming rainfall days only. You leave the drying days — often the majority — on the table.
4. Claiming every wet day. Overreach invites the GC to attack the whole claim. Claim the days you can defend individually.
5. Reconstructed logs. Contemporaneous records or nothing.

Ilystics provides weather and soil analysis, not legal advice. Contract interpretation, entitlement, and damages are questions for your attorney or claims consultant. Our reports are built to support that work, not replace it.