Met Office weather warnings for event organisers

What the colours mean

The Met Office issues warnings through the National Severe Weather Warning Service. Each is given a colour depending on a combination of both the impact the weather may have and the likelihood of those impacts occurring.

It issues them up to seven days ahead for rain, thunderstorms, wind, snow, lightning, ice, extreme heat and fog.

• Yellow: issued for a range of situations. Many mean a high likelihood of some moderate impacts. Others mean much more significant impacts are possible with a lower certainty. The Met Office says it is important to read the content of yellow warnings.
• Amber: an increased likelihood of impacts that could disrupt your plans, with possible travel delays, power cuts and risk to life and property. The Met Office says to think about changing your plans.
• Red: dangerous weather is expected. The Met Office says to take action now to keep yourself and others safe.

Source: Met Office: Weather warnings guide

A warning is not a wind speed

Because the colour combines impact and likelihood, the Met Office guide ties no colour to a fixed wind speed. Two yellow wind warnings can describe very different days. The detail is in the warning itself and in its impact and likelihood matrix, which the Met Office says to check.

The Met Office notes that the matrix changed slightly in October 2026, with new impact level wording shared with the UK's hydrological agencies and the Flood Forecasting Centre.

Source: Met Office: Weather warnings guide

How event rules use warnings

• PIPA recommends that an inflatable is not used while a Met Office weather warning is in force.
• St Albans closes its market at a yellow warning where speeds or gusts of wind are predicted to reach 35mph or above. For a warning issued more than 48 hours ahead, it makes no decision until 48 hours before the market.
• Bromsgrove cancels its market under a red warning. It says a severe weather warning in itself is not a reason to reduce or cancel the market.
• Edenbridge also says a severe weather warning in itself is not a reason to cancel the market. Its process starts from the forecast gust instead.

Sources: PIPA: Operations Manual IS0010-200, February 2026; St Albans City and District Council: Market Inclement Weather and Exceptional Circumstances Policy, adopted 21 June 2022; Bromsgrove District Council: Management of Markets in Severe Weather Policy (undated); Edenbridge Town Council: Market Gazebos and Structures including in Adverse Weather Policy, adopted 3 March 2025

Other warning systems

Flood warnings in England come from the Environment Agency. They use three levels: flood alert, flood warning and severe flood warning.

UKHSA's hot weather advice for events points organisers to its Heat-Health Alert system, which gives yellow, amber and red alerts. The Met Office says its Extreme Heat Warning, the heat-health alert and the heatwave definition are three different things.

Sources: Environment Agency: Real-time flood-monitoring API reference; UK Health Security Agency: Hot weather advice: mass gatherings and planning events; Met Office: Weather warnings guide

Getting the warnings

The Met Office publishes warnings on its app and website, by email alerts, on social media, TV and radio, by RSS and through the NSWWS API.

Source: Met Office: Weather warnings guide

What to compare

A structure's limit is a wind speed. A warning tells you severe weather is possible in your area and how likely its impacts are. The forecast gust for your site tells you whether a structure is near its limit. Read both, then follow whatever your own policy says about warnings.