All eyes are on the skies in the Indian sub-continent where the monsoon has stalled in its northward advance. About half the sub-continent has been left dry in a searing heatwave, with 48C (118F) recorded in Delhi last week; the heat has claimed more than 100 lives. Even where the monsoon has broken, the rainfalls are below normal, and there are fears of crop failures leading to soaring food prices. About 600 million people in India depend on the rains for farming, and agriculture accounts for a sixth of the national economic output. Prayers for rain are being held, and farmers in Nagpur, central India, have organised weddings of frogs, believed to please Indra, the rain god, to bring rain.

Deluges of rain across Central Europe have caused flooding in the Czech Republic where ten people have died, and torrential rain has also hit Romania, Austria, southern Germany and Poland. In Vienna the heaviest downpours for 50 years obliged the Albertina Museum to move thousands of artworks as heavy rain leaked into its basement.

The storms are being driven by a clash of hot, humid air hitting much colder air aloft. A similar weather pattern also hit western areas of Britain and turned the start of the Glastonbury open-air music festival into a mudbath.

In the US, blazing heat from Wisconsin to Florida set new temperature records for June in several places, including 40C (105F) in Austin, Texas, and triggered thunderstorms that produced hail as large as tennis balls. But sunsets in Florida and the Caribbean could be spectacular over the next few days as a vast plume of dust from the Sahara sweeps across the Atlantic. The dust produces vivid red sunsets and also helps to choke off tropical storms and hurricanes.