This year's peak summer season coincides with the U.K.'s referendum on whether to stay in the European Union (EU). And with uncertainty looming over the outcome of the vote, holidaymakers may be pondering over when is the best time to buy currency for their vacations.
"No one can know for sure what will happen come Friday when the referendum results are announced or how the results will impact the British economy," David Swann, Travelex's head of pricing for the UK, Europe and the US, told CNBC.
"However, generally speaking, since referendum campaigning began in February, we've noticed a correlation with the pound strengthening against major currencies like the euro and the US dollar when the polls have indicated that the 'remain' vote is in the lead and vice versa."
Experts say sterling will fall if Britain votes to exit the EU. According to the Economist magazine, a Bloomberg poll early in the campaign found that the majority of economists thought the pound would fall to between $1.25 and $1.35.
"Our view is that it's probably in the range of $1.35 if there is a Brexit, $1.50 if there isn't, at best," Amherst Pierpont Securities' Robert Sinche told CNBC.
"If Britain votes to leave, then sterling is particularly vulnerable," said Stephen King, senior economic advisor at HSBC, to CNBC on Tuesday.
A fall in the value of the pound would mean people coming into the U.K. would get more value for their foreign currency while those leaving the U.K. would get less foreign currency for their pounds. Brexit could therefore be good news for the U.K. tourism industry but less good for short-haul airlines and tour operators.
"During the campaigning period, the pound has been really volatile against major currencies. Even if you look at today's (Tuesday's) rate versus how it was over the weekend, the pound is up 2.3 percent against the US dollar and 1.4 percent against the euro. Which, by market standards is a significant shift over a short amount of time," said Swann.
In a note released this week, billionaire investor George Soros wrote that if Brexit goes through, "To start off, sterling is almost certain to fall steeply and quickly if leave wins the referendum… It is reasonable to assume, given the expectations implied by the market pricing at present, that after a Brexit vote the pound would fall by at least 15 percent and possibly more than 20 percent, from its present level of $1.46 to below $1.15 (which would be between 25 percent and 30 percent below its pre-referendum trading range of $1.50 to $1.60)."
"If sterling fell to this level, then ironically one pound would be worth about one euro – a method of "joining the euro" that nobody in Britain would want."
Support for Britain remaining in the EU stood at 53 percent with support for quitting the bloc at 46 percent, according to a latest ORB poll for the Daily Telegraph newspaper.
"So when is the best time to buy? If only I had a crystal ball!" Swann told CNBC.