Wildlife charity the RSPB is urging the public to provide fresh dollops of mud in their gardens to help birds struggling to build nests in the dry spell.
The driest April on record has left swallows and martins, species that typically build ornate nests, without the wet mud needed to construct their homes.
The RSPB has been inundated with reports of house martins inspecting old nests from last season but not finding any mud to repair them.
Dry weather can also result in nests falling from walls as they lose their sticking ability.
In response, the RSPB is encouraging the public, already well versed in putting out food for the birds, to also offer a lid full of wet mud.
The organisation suggests putting wet mud in a shallow container such as a dustbin lid, or creating damp mud at the edges of borders and ponds or in bare patches of grass.
As well as using it to start new nests, birds will be able to use the mud to mend existing ones.
John Day, RSPB urban adviser, explained: "The dry spell has made it extremely tricky for lots of birds to build nests and fix their old ones.
"Without the right materials to make their nests it could affect their chances of breeding successfully."
House martins use pellets of mud to build a dome shaped nest under the eaves of houses.
They usually rely on gathering mud from the edges of water bodies such as muddy puddles on tracks and in farmyards, but the dry weather means they are few and far between, so man-made muddy patches will be important.
House martins and swallows, freshly arrived from Africa, often produce two or three broods over the summer, so a strong nest is vitally important.
Martin nests also have a tendency to fall with the young still inside. The dry spell is likely to see this happening frequently as the mud dries out, reducing the nests' grip on the wall.