After London, they will continue their journey north to Greater Manchester and then travel through Scandinavia to the Arctic Circle.
"Despite the rain over the weekend, levels remain low and we are encouraging people to be aware of the impacts of drought as we enter the summer period," an Environment Agency spokeswoman said."With further unsettled periods and rainfall over the coming weeks we will continue to closely monitor the situation," the spokesman added.
The move to drought status for the region was only revealed on Wednesday, and comes following a period classified as "dry weather status", which began on 30 April.The agency has warned that drought could put a strain on water resources, lead to dead fish and algal blooms, as well as causing problems in rivers for wildlife trying to move upstream due to reduced flow.It has a drought plan in place to manage the dry weather, and to regulate United Utilities to "make the best use of available water whilst also protecting the environment".
A spokesman for the water firm, which supplies water to millions of people across the region, said demand had reduced due to the water-saving efforts of customers, combined with recent rainfall and cooler temperatures.But reservoir levels remained "lower than we'd expect at this time of year and so we're continuing to move water around our integrated network to get it to where it is needed," he added.
Extra water is also being brought into the system for other sources around the region.
The spokesman said: "Leakage is at its lowest level and we're repairing record volumes, with customers supporting us by reporting more leaks."Our current government… they are really enforcing this kind of public-private collaboration," says the programme's director Kirsi Kokko. "I think they understand the urgency."
Despite the rapid growth of defence tech in Finland, the sector is facing a range of local and European-wide challenges.Mr Hietala, the founder of airship technology platform Kelluu, describes something of a "culture clash" between agile start-ups and large defence companies and governments that have typically required years of experimentation and prototyping before acquiring new technologies.
"That's really on the opposite side of the spectrum for start-ups, in which the DNA is that we will fail fast and rapidly, and you don't have every start-up succeed."At Business Finland, Ms Kokko says the Nordic nation is also impacted by strong global competition for the software talent needed to grow defence tech and dual use businesses.