One of the warmest springs on record could set up a good summer for butterflies, charity says as it launches 2026’s Big Butterfly Count.
The UK could be heading for a bumper butterfly season – and even a “painted lady summer” – conservationists say as they urge people to join a national count for the insects.
Wildlife charity Butterfly Conservation said that a warm, dry spring this year has raised hopes that butterflies could be out in force this summer.
But it wants members of the public to join its annual Big Butterfly Count, from July 17 to August 9, to help reveal exactly how butterflies are faring this year.
The annual citizen science survey helps scientists understand where some of the country’s most common butterflies and day-flying moths are doing well, struggling or moving because of climate change and changes to habitat.
Butterfly Conservation said heatwaves, warm dry spells and the occasional heavy rain have created ideal conditions for butterfly breeding and caterpillar growth, with small coppers and holly blues already seen in large numbers and peacock, red admiral and brimstones having a promising start to the year.
Experts at the charity also say there are signs of a possible “painted lady summer” – when the migrant butterfly arrives in the UK in large numbers – but they need people across the country to tell them what they are seeing to know for sure.
The hopes for a good summer for the winged insects mark a reversal from just two years ago, when the charity declared a “butterfly emergency” after the 2024 count delivered the worst results in the scheme’s history.
A hot, dry, and sunny 2025 boosted the fortunes of many species, and this year’s spring – one of the hottest on record – could prove a boon for butterflies.
But Butterfly Conservation says that is not guaranteed – and the charity warns it comes against long-term declines.
Four fifths (80%) of butterfly species have declined in the past 50 years, as a result of habitat loss, pollution and climate change, the conservationists said.
Butterfly Conservation’s head of engagement, Kate Merry, said: “After the colourful spring with seemingly lots of beautiful butterflies appearing across the UK, it’s tempting to assume we’re heading for a bumper summer, and we’d love nothing more as most of our butterfly species have undergone long-term declines.
“But a bright spring is only ever part of the story, which is why we need people out there taking part in the Big Butterfly Count this summer.
“We genuinely don’t yet know how this year will unfold, and the only way to find out is for people to tell us what they’re seeing in their own gardens and green spaces.”
She added: “Butterflies are icons of summer and, more importantly, key indicators of the UK’s biodiversity and environmental health.
“Every single person that takes part in the Big Butterfly Count and submits their sightings is helping us to see how these pollinators are doing, which in turn helps conservationists build a wider picture of how all insects are faring.”
To take part in the Big Butterfly Count, people just need to spend 15 minutes in any sunny outdoor spot, such as their garden, park or local countryside, and report their sightings.
For more information and to take part people can download the free Big Butterfly Count, or visit bigbutterflycount.org.
