Some 449,000 people bought Christmas puddings in September, according to figures from market researcher Kantar.
Sales of the festive staple were up 76% compared to the same month last year.
It was not clear whether consumers were preparing to keep their pudding until 25 December, or whether they simply enjoy a good Christmas dessert all-year-round and planned to devour it as soon as possible.
The Kantar figures, which compare the four weeks to 5 September 2021 with the four weeks to 6 September 2020, also showed that toy sales were up 5% and sales in gift-wrapping products increased by 10%.
Sales of frozen stuffing were 37% higher, frozen poultry and game were up 35%, and seasonal greeting card sales were up 25%.
It comes amid concerns that some shop shelves might be empty as Christmas gets closer, with the country's supply lines hampered by a shortage of truck drivers.
But Fraser McKevitt, Kantar's head of retail and consumer insight, said the sales figures were "still relatively small numbers and anxiety around supply issues has not translated to panic buying - festive or otherwise".