Hotel prices soared during the air travel lockdown prompted by volcanic ash last week, as thousands of people scrabbled to find accommodation in crowded hotels.

Research by price comparison site Trivago revealed that prices in cities such as Milan jumped by 90 percent during the week of April 15-22, leaving stranded travelers to shell out £200 (€230) a night for accommodation in the city.

Although Milan was also hosting the Football Championship League Semi-Finals on April 20, the hikes were widespread across the affected area, suggests Trivago.

An overnight stay in London during the airline grounding averaged out to £205 (€236) a night; compared to April's expected average of £138 (€159), this represents a climb of 49 percent.

Stranded travelers in Berlin faced surcharges of 63 percent, seeing prices rise from £84 (€96) at the beginning of the month to £137 (€158).

Hoteliers in Madrid raised prices 46 percent as a result of the travel crisis, while those travelling or trapped in Paris were also forced to dig deep into their pockets - room prices rose by 27 percent, from £138 (€159) at the beginning of the month to £175 (€201).

With scientists warning that there may be further eruptions to come, Trivago spokesperson Romain Hefti says that it pays to be prepared.

"In situations like this, there is a very small window of opportunity before everyone realizes they need a place to stay. Once the rush starts, being able to cover as many hotels as possible improves your chances considerably. Since hotel metasearch sites like Trivago show live room availability, these are definitely your best bet."

Other options for travelers include heading for the hills - prices outside of European travel hubs are unlikely to rise as much as the packed inner-city and airport accommodation options.

Faraway friends able to provide a bed can also come into their own in these situations, and even remote contacts can help; London university King's College London, for example, sent out emails to disparate ex-students urging them to help fellow alumni.

And for travelers by themselves, even having an internet connection is useful - 30,000 visitors flooded the site with requests for accommodation in the aftermath of the airspace closure.