Could the National Trust's Ickworth House be closed for a siesta during summer lunchtimes? Will Sutton Hoo stage more events in March and October in future years as climate change becomes a reality?

The country's largest heritage organisation is looking at changing the ways it opens to the public after completing major research among visitors to its properties.

Its attractions in the south and east of England are expected to be the most seriously affected as temperatures rise and the threat of flooding and drought increases.

The National Trust analysed data from more than 85 million visits, before the pandemic, to 170 of its coastal and countryside sites, castles, stately homes, gardens and historic buildings across England, Wales and Northern Ireland.

It compared the visitor data with the weather conditions and discovered that a quintessential “National Trust day” across all its locations is one with temperatures of 21C (70F), moderate winds and a very small amount of rain.

It also found people preferred visits to indoor properties at 20C (68F), and above that the numbers of people choosing to go to stately homes and other historic buildings starts to decline.

While people flock to outdoor locations, particularly beaches and coasts, in warmer weather, around 24C (75F), numbers decline above this dramatically reduce once temperatures hit 28C (82F).

The Trust said that climate change could mean more visits to sites at current “off peak” times as spring and autumn become warmer and summer becomes too hot.

One of its large houses in southern England closed in the middle of the day during the hot summer of 2019 because visitors did not want to come inside in stifling heat.

A spokeswoman for the Trust in the East of England said: "Many of our places are already open all year round, like Sutton Hoo and Dunwich Heath.

East Anglian Daily Times: Sutton Hoo in summer - but could more emphasis be put on spring and autumn visits?Sutton Hoo in summer - but could more emphasis be put on spring and autumn visits? (Image: Archant)

"However, we'd need to look at how our offer adapts to accommodate changes in visitor patterns. This could mean that more people come out to enjoy the spring blossom at places like Anglesey Abbey and Wimpole, or we make more of the spectacular autumn colour at Ickworth.

"Families too may consider May half-term and October half-term more important for their get-away break. It’s clear from this research that there’s a lot for us and the UK tourism industry to think about and prepare for the effects of climate change.

National Trust head of climate and environment Lizzy Carlyle said: “What this data shows us is that we have a lot to do to prepare the UK tourist industry for the effects of climate change.

“Much of the debate around tourism and climate change to date has rightly focussed on international travel and the impact flights and foreign holidays is having.

“But what hasn’t been fully addressed is what the domestic tourism industry could be facing unless we take drastic action to reduce emissions.”