Other vegetables, including broccoli, artichokes and aubergines, also known as eggplants, have been hit.
Many European countries rely on the Spanish regions of Murcia, Almeria and Valencia for the supply of these and other vegetables during the winter months. A shortage of zucchini, also called courgettes, caused by the same spell of bad weather recently prompted consumers to take to social media using the hashtag #courgettecrisis.
"Southern Spain is the bread basket for Europe in the winter," Anthony Gardiner of G's
, a major supplier of fresh produce to supermarkets across Europe, told CNN. "It has its own micro-climate. It's warm and dry, almost desert-like."
But this winter has been different.
"We've seen horrific weather on our farms in the Murcia region," Gardiner said. "Over four days just before Christmas, the region had the same amount of rainfall that London gets in six months. It was an absolute deluge, and a lot of crops were washed away."
A cold snap pushing across southern Europe over the New Year period compounded the problems.
"We saw snow on the beaches in Murcia," Gardiner said. "In those conditions, the produce effectively stops growing. We're now seeing that starting to hit the shelves."
Fernando Gomez, general manager of Proexport
, an association of more than 50 producers and exporters of fruits and vegetables in Murcia, told CNN that supply of lettuces from the region had fallen by 40% due to the bad weather. Supplies of artichokes and broccoli are down by 20% to 30%. Vegetables grown in greenhouses including tomatoes and cucumbers are also affected.
Produce that has survived the heavy rains and freezing temperatures is now growing slower due to unusually high humidity levels, Gomez explained. "We are replanting now, but the produce will take longer than normal to mature -- 70 to 80 days -- if the weather doesn't change."
According to Gomez, other European countries make up 90% of the market for the region's vegetables. More than half of those exports go to the UK and Germany alone, while France and the Netherlands also rely heavily on Spanish vegetables.
Some UK supermarkets are restricting the number of lettuces each customer can buy, and prices have also risen sharply. German consumers are now paying €2 (about $2.15) for a head of lettuce, according to Gardiner, up from 75 cents
"We're shipping over Californian lettuces to try to meet the demand," Gardiner said. "But this means we're creating extra demand in that market, which is also pushing prices up. It's a very challenging situation."
It is not only consumers who are feeling the effects.
"People in Murcia have been badly affected by the weather," Gardiner said. "Some farmers have been washed out of their houses by the floods."
And with lettuce as Spain's biggest vegetable export
, there could be broader economic consequences, too.
Gardiner predicts that supply will only return to normal in April or May, when produce grown in Britain and other European countries becomes available.
Gomez is more hopeful.
"We're already seeing the prices of some affected products falling, such as cucumbers," he said. "I hope supply will be back to normal by the end of March."
"There are very good reasons to grow these crops here," Gomez said. "We've got the sun, the expertise and a history of being able to produce the kind of crops that can't be grown elsewhere in Europe at this time of year. That's not going to change."