Whatever the weather: Inclement weather in the context of construction

Co-authored by Suzanne Chinner and Sandra Hugo


“Concrete is, essentially, the colour of bad weather.”

William Hamilton

Inclement weather – a Global Risk

Each year the World Economic Forum publishes a Global Risks Report which identifies and analyses the most pressing current global risks based on input from nearly 1,000 experts across the world. These risks are categorised and ranked according to likelihood and impact; the top five (5) risks are shown in the extracts below:

Source: World Economic Forum (2021),
Figure I: The Evolving Risks Landscape, 2017–2021 [i]

Notably absent from the tables above is the risk of infectious diseases from 2017 to 2020. That is to say, according to nearly 1,000 experts from around the world, infectious diseases did not even feature among the top five (5) risks in terms of likelihood or impact. With the assistance of hindsight and the widely recognised impact of the Coronavirus pandemic, the 2021 Global Risks Report lists infectious diseases as the top threat in terms of impact and fourth in terms of likelihood. This is significant as it demonstrates that not all risks can be foreseen, which makes it even more important to deal with those risks that are foreseeable (e.g. extreme weather).

As shown above, extreme weather has been ranked as the top global risk in terms of likelihood since 2017, outranking other serious global threats such as climate action failure, natural disasters etc. Extreme weather also ranks high in terms of impact, which, together with its top rank in likelihood, makes this a major current global risk.

The 2020 Global Risk Report[ii] goes on to say that:

“The last five years are on track to be the warmest on record, natural disasters are becoming more intense and more frequent, and last year witnessed unprecedented extreme weather throughout the world”.

While the impact of extreme weather events has become more unpredictable over the last few years as a result of global warming, this is by no means a new occurrence. In fact, inclement weather events have been recorded in some of the earliest historic records and continue to make headlines today.


Inclement weather in the context of construction

Construction projects around the world are affected by inclement weather, including rain, snow, extreme cold or heat, strong wind, thunderstorms etc. Essentially, inclement weather includes any weather conditions that would make it impossible, unsafe or unreasonable to continue with construction activities. Naturally, construction activities taking place outdoors have greater exposure to severe weather conditions.

In the case of Fraser Construction Company v. United States (2003)[iii], the court defined inclement weather as “weather more severe than might be anticipated for the project location during the period of expected performance.”

Holman (2008)[iv] defines inclement weather as:

“Weather which at the time of the year in which it occurred is unusual for the place in which it occurred. No matter how severe or destructive, if the weather is not unusual for the particular time and place or if the Contractor should have reasonably anticipated it, the Contractor is not entitled to relief.”

It is widely accepted that inclement weather is a major cause of delay in construction activities. Yet, for reasons unknown, parties to construction contracts often fail to recognise the risk associated with inclement weather, especially on large scale projects.

This is evidenced by the fact that parties often sign up to contracts with ambiguous clauses relating to exceptionally adverse weather conditions that do not properly define inclement or extreme weather and clauses that do not clearly state how the impact of these events should be recorded, measured or dealt with contractually.

When dealing with a risk that is likely to occur, with a big potential impact when it does, why would parties to a contract not take necessary steps to identify and manage these risks when they occur?


Pre-contract considerations

When identifying risks related to inclement weather, the following questions should be considered:

Simple Risk Model
  • What – Refers to what is being constructed (i.e. the type of project). A new road construction or erection of wind turbines will be more exposed to weather risks than, for example, a hotel refurbishment with mostly indoor (climate controlled) construction activities.
  • When – Provides further information as to the contract duration and time of the year, which will have an impact on expected weather conditions.
  • Where – Refers to the project location, which will assist in identifying project specific weather risks.
  • How – Includes consideration of the planned construction methods. For example, cranes and working at heights will be affected by wind conditions, while precast / prefabricated structures will be less affected by inclement weather.

Contracting parties should understand how weather risks are allocated before entering into a contract. For example, is it a neutral event which entitles the contractor to extension of time or is the contractor also entitled to claim additional costs? Parties should also understand exactly what inclement weather means in the context of a specific project and how its effects should be measured.


Historical information

Modern technology, statistical databases and easily accessible historical records have significantly improved the accuracy with which weather patterns can now be anticipated. These records can help to determine what is considered normal (or foreseeable) in order to provide a baseline from which any inclement weather occurrences can be measured against.

The Australian Government Bureau of Meteorology (BOM) provides a myriad of historical information on the Australian weather and climate, dating back decades. The BOM data include records on trends, highs, lows and averages of rainfall, temperature, wind etc. across numerous locations. The data can be expressed on a daily, monthly or yearly basis.

Contracting parties can therefore easily access data in order to identify any weather risks associated with a specific location and time of year. For example, the graphic below which shows the annual average daily maximum temperatures across Australia.

Average daily maximum temperature (Annual)
Source: BOM (2020) [v]

With an average daily temperature of above 33 degrees, a project in the Northern Territory, for example, will likely suffer delay and / or disruption as a result of hot weather. Whereas the graphic below highlights the likelihood of wet weather delays in Tasmania, with an annual average of 75 days with rainfall greater than 10mm.

Average number of rainfall days (Annual)
Source: BOM (2020) [vi]

Once the risk has been identified, further investigations can follow. For example, the chart below which shows the highest, lowest and average rainfall over the last ten years in Hobart, Tasmania.

Hobart average rainfall (2011 – 2020)
Source: BOM (2020) [vii]

Armed with this knowledge, a contractor should be able to make sufficient allowance for foreseeable wet weather in its programme and project budget.


Practical considerations

Regardless of the type of project, its location or the form of contract used, it is suggested that the following be incorporated into the contractual agreement:

  • a clear definition of what constitutes inclement weather;
  • express provisions as to which weather events are included and which are excluded;
  • the exact location where weather events will be recorded;
  • the source of data for actual and historic records (e.g. BOM);
  • how inclement weather will be measured (e.g. cumulative rainfall per month, number of working days with rainfall of more than 10mm etc.);
  • how the baseline for historical weather will be measured (e.g. average rainfall in a specific location over the last ten years, etc.); and
  • clear provisions for how inclement weather events will be dealt with under the contract.

Proper records of weather events should be kept and updated regularly to assist with any claims which may need to be made. Site records that are vague / unclear will not provide sufficient evidence to support claims for inclement weather.

Site diaries usually include an entry for weather, however, these entries are usually very vague, e.g. by describing the weather as ‘rainy’ or ‘windy’. In the case of rain, it is important to record when the rain started and ended, how much rain was recorded, and the areas of work and activities affected.

Videos or time-lapsed photographs can also be a useful tool to demonstrate weather conditions and provide a visual history of the project’s weather conditions.


Concluding remarks

Inclement weather is a global problem that frequently impacts construction projects. While weather cannot be controlled, the risks associated with inclement weather can be managed in such a way to avoid these events from escalating into disputes.

Contractors should keep (and regularly update) accurate records of actual weather conditions for the duration of the project and if a contractor believes that it is entitled to additional time and / or cost resulting from inclement weather, notice should be given in accordance with the contract provisions.

Before entering into a contract, parties need to identify the weather risk specific to each project and should ensure that the contract provisions clearly and unambiguously deal with inclement weather. This includes a clear definition of what is considered to be inclement weather, the mechanism for dealing with weather events and what the division of risks are.

However, despite clearly set out definitions and a mechanism to deal with inclement weather, contractors can still be exposed to substantial losses. In Aston’s experience, the “rainy day” can be the tip of the iceberg as there are other factors that need to be carefully considered and understood by the parties, e.g. the affects / aftermath of wet weather, insurance considerations / limitations etc.

This article introduced the topic of inclement weather and its importance in terms of construction projects. The next article will further expand on the topic including issues relating to legal and contractual aspects. Case studies will also be included to further explore the issues relating to inclement weather and its potentially devastating financial ramifications (if not adequately prepared for).


[i] World Economic Forum (2021) ‘The Global Risks Report’. Available at: http://reports.weforum.org/global-risks-report-2021/survey-results/the-global-risks-landscape-2021/

[ii] World Economic Forum (2020) ‘The Global Risks Report’. Available at: http://www3.weforum.org/docs/WEF_Global_Risk_Report_2020.pdf

[iii] Fraser Construction Company v United States [2003] 57 Fed. Cl. 56.

[iv] Holman M (2008) ‘Weather delays: snow & rain & hail, oh my!’. Available at: https://www.lexology.com/library/detail.aspx?g=9acac71d-a90f-4bc5-bbcb-5d5366ed4cfa

[v] Bureau of Meteorology (2020) ‘Average annual & monthly maximum, minimum, & mean temperature’. Available at: http://www.bom.gov.au/jsp/ncc/climate_averages/temperature/index.jsp

[vi] Bureau of Meteorology (2020) ‘Average annual & monthly days of rain’. Available at: http://www.bom.gov.au/jsp/ncc/climate_averages/raindays/index.jsp?period=an&product=10mm#maps

[vii] Bureau of Meteorology (2020) ‘Daily rainfall – Hobart Botanical Gardens‘. Available at: http://www.bom.gov.au/jsp/ncc/cdio/weatherData/av?p_nccObsCode=136&p_display_type=dailyDataFile&p_stn_num=094030&p_startYear=

2021-05-04T02:40:13+00:00 May 4th, 2021|Insights, News|0 Comments