This is the 12th year of initiative, which began yesterday (Friday June 16) and runs until next Sunday (June 25).
Deliberately covers two weekends, the scheme aims to inspire the public to get out and enjoy the summer weather with a picnic.
According to the organisers, the average Brit picnics at least three times a year, and some 70% will take part in at least one picnic this summer.
Adam Cox, founder of National Picnic Week, said: “With a heatwave forecast, we’re expecting more picnics during National Picnic Week than ever before.
“Picnic Week is all about coming together and trying something new, and getting friends and families out to the best parks, beaches and scenic sites that the UK has to offer.
“In a time of economic uncertainty and with living costs outweighing wages, picnics offer the perfect alternative to dining out. Preparing your picnic at home is both great fun and can save a fortune.
“Picnics are fantastic for all. Older Brits may reflect on simpler times whilst the younger generation can take advantage of creating Instagram-worthy dishes.
“Families can create memories while also getting the kids away from computer games and into exercise and play. And couples can create the dates of yesteryear in picturesque settings.”
Picnics have changed over the years, as have eating habits. Brits are now 285% more likely to pack a tub of hummus than they were 15 years ago.
Fifty years ago the most popular picnic snack was the humble cheese sandwich. Now, it’s a bag of crisps, which is why Seabrook Crisps have partnered with National Picnic Week. Other partners for 2017 are Mrs Elswood (pickles), No-No Flatbreads, Delouis Mayonnaise and The Saucy Fish Co.
According to research conducted in 2013, the average family spends £26 per picnic.
The National Picnic Week website includes recipes as well as suggestions for food, plus advice and tips on alfresco activities and locations.
The most popular day for picnics in the US is Independence Day on July 4. In Italy it’s Easter Monday. In France, it’s Bastille Day.