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Weather Delay Notice Template for Construction: A Sample You Can Adapt

Last updated July 2026 · 10 min read

Day nine of rain. The excavation is a pond, the crane is on standby, and the programme is bleeding a day for every day the sky stays grey. Someone says what everyone is thinking: "surely we get time for this." Maybe — but only if two things are true: the weather is genuinely exceptional, and a notice goes out before the deadline does. This guide gives you the letter, the evidence bar it has to clear, and a filled-in example.

When Weather Gives You Time — and When It Doesn't

Under the FIDIC 1999 Red Book, the route is Sub-Clause 8.4(c): the Contractor is entitled to an Extension of Time for exceptionally adverse climatic conditions. Two words in that phrase do all the work, and both get misread on Site.

Exceptionally means worse than the records say to expect. Rain in the rainy season is not exceptional — a competent Contractor is deemed to have priced and programmed for normal seasonal weather. The entitlement begins where the normal range ends: the wettest July in fifteen years is a claim; an ordinary wet July is just July.

And the entitlement is time only, not money. FIDIC treats weather as a shared risk: the Employer gives up the delay damages for the lost days, and the Contractor carries its own prolongation costs. A weather notice that asks for cost is asking for something the clause does not offer — and a claim that overreaches on one limb invites scrutiny on the other.

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Key Takeaway: Weather delay runs through Sub-Clause 8.4(c) and gives time only, never cost. The weather must be exceptional against historical records for that place and season — ordinary seasonal weather is already the Contractor's risk and belongs in the programme, not in a claim.

The Evidence Bar: Beat the Records, Not the Mood

A weather claim is won or lost on a comparison. Not "it rained a lot" — but "it rained this much, against a long-term average of that much." The notice itself stays short, but from day one the file behind it needs three layers:

The weather data — daily rainfall, wind, or temperature from a recognised meteorological station near the Site, plus the long-term figures for the same month. The delta between them is the word "exceptionally" turned into a number.
The effect on the Works — site diary entries naming the activities that stopped and why, supported by dated photographs. A flooded excavation photographed on the day beats a paragraph written three months later.
The programme link — which of the stopped activities sit on the critical path. Rain that idles a non-critical crew is misfortune; rain that stops the critical path is an Extension of Time.

One measurement habit saves claims: track working days lost, not millimetres of rain. Fifty millimetres overnight that drains by breakfast costs nothing; fifteen millimetres falling steadily through a concrete pour costs the day. The diary should record the consequence, because the consequence is what the Engineer must assess.

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Key Takeaway: Build three layers of evidence from day one — met-station data against long-term averages, site diary entries with photos showing which activities stopped, and the critical-path link. Record working days lost, not just rainfall totals; the consequence is what gets assessed.

Weather Delay Notice Template — Copy and Adapt

Replace everything in square brackets, then delete the brackets. Note what the template does not ask for: cost, day counts, or the final delay figure. Those come later, in the particulars.

[Date] To: [Engineer's name and company] Project: [Project name and contract reference] Notice of Delay and Claim under Sub-Clause 8.4(c) and Sub-Clause 20.1 The Contractor gives notice under Sub-Clause 8.4(c) of the Conditions of Contract that exceptionally adverse climatic conditions are delaying the Works. The Contractor became aware of this event on [date of awareness]. Since [start date of the weather event], the Site has experienced [describe the conditions — e.g., sustained heavy rainfall / high winds exceeding crane operating limits], which is exceptional when compared against long-term meteorological records for [location] for this period. Supporting weather data is being compiled and will accompany the detailed particulars. These conditions are delaying the Works. [Identify the affected activities and why they cannot proceed — e.g., excavation for the pump station is suspended due to standing water; these activities are on the critical path.] The Time for Completion is expected to be affected. The Contractor reserves its right to an Extension of Time under Sub-Clause 8.4. Detailed particulars, including meteorological records and a programme impact assessment, will be submitted within [42] days in accordance with the Contract, or sooner if practicable. Yours faithfully, [Name] [Designation, for the Contractor]

The "[42] days" is the FIDIC 1999 default for particulars — if a bespoke contract sets a different period, use that number. And serve the notice while the weather is still happening if the 28 days demand it: a continuing event does not pause the clock on its earliest days.

This letter is also the exact document ChatNotice was originally built to draft — describe the weather and the stopped activities in plain words, and it produces the notice with the right clauses in place.

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Key Takeaway: The notice names the clause, the awareness date, the conditions, and the affected critical-path activities — and reserves the right to time. Numbers and weather data follow in the particulars within the contract's period (42 days on unamended FIDIC 1999).

Worked Example: A Filled-In Weather Delay Notice

Here is the template filled in for a sustained-rainfall event. Notice how the comparison against records is asserted briefly now and proven later.

19 August 2026 To: Ms R. Fontaine, Resident Engineer, Meridian Consulting Project: Northgate Interchange Upgrade — Contract NIU-2025-03 Notice of Delay and Claim under Sub-Clause 8.4(c) and Sub-Clause 20.1 The Contractor gives notice under Sub-Clause 8.4(c) of the Conditions of Contract that exceptionally adverse climatic conditions are delaying the Works. The Contractor became aware of this event on 12 August 2026. Since 8 August 2026 the Site has experienced sustained heavy rainfall, with recorded totals materially above long-term August averages for the region per the national meteorological service station at Northgate. Supporting weather data is being compiled and will accompany the detailed particulars. These conditions are delaying the Works. Bulk earthworks for Embankment E2 and pile cap excavation at Pier 4 are suspended due to standing water and unsafe ground conditions. Both activities are on the critical path. The Time for Completion is expected to be affected. The Contractor reserves its right to an Extension of Time under Sub-Clause 8.4. Detailed particulars, including meteorological records and a programme impact assessment, will be submitted within 42 days in accordance with the Contract, or sooner if practicable. Yours faithfully, D. Mensah Project Manager, for the Contractor

Half a page. The rainfall totals, the fifteen-year comparison, and the day-by-day programme impact all belong to the particulars — where there is time to get them right.

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Key Takeaway: A real weather notice fits on half a page: clause, awareness date, the conditions in one sentence, the stopped critical-path activities, and the reservation. It asserts that the weather is exceptional and promises the proof — it does not try to be the proof.

Common Weather Claim Mistakes

Claiming ordinary weather. The rainy season arriving on schedule is not a claim. If the long-term data does not show an exception, the notice spends credibility the Contractor will want later.
Asking for cost. Sub-Clause 8.4(c) gives time only. Attaching prolongation costs to a pure weather event signals that the claims are drafted by habit, not by clause.
Waiting for the weather to end. The 28 days run from awareness of delay, not from the last drop of rain. A six-week wet spell noticed at its end may already be part time-barred.
No baseline comparison. A file full of rain gauges but no long-term averages proves it rained — not that the rain was exceptional. The comparison is the claim.
Measuring rainfall instead of consequence. The Engineer assesses lost working days on affected activities. A diary that records weather but not which crews stood down leaves the assessment to guesswork — and guesswork favours the assessor.
One notice for separate storms. Distinct weather events carry distinct 28-day clocks. Bundling a March storm into an April notice hands the Engineer a time-bar argument for March.

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Key Takeaway: Weather claims fail six ways: claiming normal seasonal weather, asking for cost the clause does not give, serving notice only after the weather ends, having no long-term baseline to compare against, recording rainfall instead of lost working days, and bundling separate storms under one notice.

Frequently Asked Questions

Does a weather delay give the Contractor extra money as well as time?

No. Under the FIDIC 1999 Red Book, exceptionally adverse climatic conditions fall under Sub-Clause 8.4(c), which entitles the Contractor to an Extension of Time only — not Cost. That is deliberate: weather is treated as a shared risk, with the Employer carrying the time and the Contractor carrying the money. If a notice claims prolongation costs for pure weather delay, it is claiming something the clause does not give, and it invites a rejection that taints the valid part of the claim.

What counts as exceptionally adverse weather?

Weather that is materially worse than what historical records for that location and season would lead a competent Contractor to expect. Rain in the rainy season is not exceptional — it should be in the programme already. The practical test is a comparison: this month's rainfall, wind, or temperature against long-term data for the same month, from a recognised meteorological source. If the numbers are within the normal seasonal range, the entitlement is weak no matter how disruptive the weather felt on Site.

What evidence should support a weather delay notice?

Three layers. First, the weather itself: daily records from a recognised meteorological station near the Site, plus the long-term averages the actual weather is compared against. Second, the effect on the Works: site diary entries showing which activities stopped and why, with photographs. Third, the programme link: which affected activities sit on the critical path. The notice itself stays short — but these records must exist from day one, because they are what the detailed particulars are built from.

When does the 28-day notice clock start for a weather delay?

From when the Contractor became aware, or should have become aware, that the weather event was causing delay — not from when the rain started. In practice that is usually when work on an affected activity is first disrupted. Do not wait for the weather to end: a prolonged wet period can run longer than 28 days, and a notice served only after the skies clear may already be out of time for the earliest losses.

Can one notice cover a whole month of bad weather?

A single continuing event — one exceptionally wet month, one cyclone and its aftermath — can be noticed once, with the notice describing the continuing effect and the particulars updating the impact as it develops. But separate weather events need separate notices, each within its own 28-day window. When in doubt, serve another notice: a redundant notice costs a page, while a missed one can cost the entitlement.

Authoritative Sources

This guide reflects the FIDIC Conditions of Contract and established construction-law guidance. For the primary materials, see:

FIDIC Conditions of Contract — the official contract suite published by the International Federation of Consulting Engineers, which sets out the Sub-Clause 8.4 Extension of Time grounds including exceptionally adverse climatic conditions.
SCL Delay and Disruption Protocol — the Society of Construction Law's guidance on contemporaneous records and the assessment of delay to the critical path.

About the Author

Maisam Jiwani is a Project Director with 15 years' experience on major infrastructure and energy projects administered under FIDIC contracts. He writes from first-hand experience serving notices and managing contractual claims on live projects.

Serve the weather notice before the clock runs out.

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