Category: Parametric insurance · Reviewed by Tim Roche, Director · PI & Commercial · Last reviewed 2026-06-10
Parametric weather insurance is a class of parametric insurance under which the trigger and payment are calculated by reference to meteorological indices — temperature, rainfall, wind speed, sunshine hours, cumulative degree-days — measured at defined weather stations or derived from reanalysis datasets. It is the most commercially established category of parametric cover in the United Kingdom and continental European markets, used by energy traders, agribusinesses, event organisers, brewers, ski operators and renewable generators.
Category: Parametric insurance Also known as: Weather index insurance, parametric weather cover, weather derivative insurance Established / Coined: Weather index contracts from the late 1990s (Aquila Energy 1997); commercial parametric weather insurance from circa 2005 Related concepts: Parametric insurance, Parametric heat insurance, Parametric solar irradiance, Parametric wind energy
A parametric weather insurance contract pays a sum (typically calculated as a unit value multiplied by the units by which the index exceeds or falls below a threshold) on the measurement of a defined meteorological index over a defined period at a defined station or grid cell. Indices used in commercial UK and European practice include: cumulative rainfall (mm), mean or maximum temperature (°C), heating-degree-days and cooling-degree-days, wind speed (m/s), sunshine hours, snowfall (cm), and frost-day counts.
The contract specifies the data source (e.g. UK Met Office stations on the MIDAS network, ECMWF ERA5 reanalysis, EUMETSAT satellite-derived products), the index calculation method, the strike, the limit and the settlement timing. Settlement typically occurs within 14-30 days of the index period closing.
Parametric weather insurance is insurance under English law where the St Christopher test ([1974] 1 WLR 99) is met and the insured has an insurable interest under Marine Insurance Act 1906 s.4 or Life Assurance Act 1774 s.1. Where insurable interest is absent the contract is a weather derivative — an OTC derivative regulated under the FSMA 2000 (Regulated Activities) Order 2001 article 83 and within scope of the UK MiFIR transparency regime.
This insurance/derivative boundary is the subject of the EIOPA Discussion Paper on parametric insurance (June 2023), which confirms that parametric weather contracts written by EEA insurers are within Solvency II scope, subject to PRA SS5/16 internal-model rules in the UK. Conduct rules under ICOBS 5 (demands and needs), ICOBS 6 (information requirements) and the Consumer Duty apply to UK retail sales, with particular emphasis on basis risk disclosure.
A UK brewer, for example, contracts a parametric cover triggered by mean July-August temperature at the Heathrow MIDAS station falling more than 1.5 °C below the ten-year average, paying GBP 100,000 per 0.1 °C up to a GBP 1.5 million limit. The contract sets out the data source (Met Office published data), the calculation methodology (mean of daily mean temperatures), the dispute mechanism (independent expert appointed by the AIDA UK or CIArb), and the settlement timeline.
For larger commercial weather books, MGAs such as Speedwell Weather, Skyline Partners and Descartes Underwriting structure contracts using ERA5 (the ECMWF fifth-generation reanalysis) as the index source where station coverage is poor or to avoid manipulation risk.
Variations include cooling-degree-day and heating-degree-day contracts (for energy retailers and utilities), wind-speed shortfall contracts (for wind farms — see parametric wind energy), low-irradiance contracts (for solar developers — see parametric solar irradiance), and event-day rainfall contracts (for outdoor events, weddings, festivals). The 2022 and 2023 European heat events drove growth in high-temperature parametric cover (parametric heat insurance).
A London-based outdoor music festival purchases a parametric rainfall cover from a Lloyd’s coverholder. The trigger is cumulative rainfall greater than 25 mm at the festival’s site (Reading MIDAS station) over the 72 hours of the event. On trigger, the policy pays GBP 750,000, settled within 14 days of the event close. The Lloyd’s slip references the Met Office daily rainfall publication and an independent expert dispute mechanism. The placing broker’s demands and needs statement records the residual basis risk between the airport station and the festival site.
This entry is part of the Apex Insurance Wiki. Last reviewed by Matt Bartlett on 2026-06-10. Next review: 2026-12-10.
Apex Insurance Brokers Limited. Authorised and regulated by the Financial Conduct Authority, FRN 724952. Registered in England and Wales, Companies House 07014570. This entry provides general information about UK insurance concepts and is not regulated advice. Consult your insurance broker on your specific position.
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