This could be a spectacular weekend for toad-watching. Torrential rains will soak the entire UK and could trigger a mass migration of toads to their ancestral breeding ponds.

So far this year toads have been having a frustrating time. They usually emerge from their winter hibernation sites from February onwards and migrate along the same routes to the same ponds each year to mate. Toads are cautious animals, though, because they do not want to risk breeding in ponds that later get hit by frost, which kills off the spawn. So they wait for a few days of temperatures above about 5C (41F) with warm nights as the signal to start their travels.

The wildlife charity Froglife collects reports of toad migration from the public across the UK, and their survey shows that peak migrations so far have only happened in the far South West of the country. Although average temperatures have been good, the toads also need rain, and this has been in fairly short supply over the past several weeks. This is because high pressure has been dominating the weather, especially in the southern half of Britain. Last month’s rainfall for England and Wales was about a third lower than normal, in the sunniest February on record. March began much the same way, but conditions are now shifting to an Atlantic airflow, bringing some very wet and stormy weather.