Nearly five and a half million passengers passed through Heathrow in February, as the airport repeated the need for it to expand quickly.
Emerging markets in South Asia and Latin America increased by 12.7 per cent and 6.5 per cent respectively, while strong markets in North America and East Asia meant trade was up 5 per cent, allowing February to mark Heathrow's 19th consecutive month of record cargo growth.
Domestically, Flybe carried an extra 17,000 passengers last month, a growth rate of 3.6 percent.
The airport said Britain's infrastructure was feeling the strain from the record cargo performance and that Heathrow needed to act swiftly to absorb the pressures. Six of of the UK's key trading routes - including Shanghai, Tokyo Haneda, Delhi, Mumbai, Los Angeles and Dubai - wee already full, it said.
Heathrow CEO John Holland-Kaye said: "Today's figures show that Heathrow is filling up fast - if we don't act soon to expand our nation's global gateway, the UK will only fall further behind our European rivals. A prosperous, global-trading Britain needs an expanded Heathrow now."
Heathrow is hoping to progress with expansion plans after receiving the green light from government in October 2016. The government intends to put its airports national policy statement before MPs in the first half of this year.
The airport is not only seeking win over public opinion. It is also trying to garner the support of airlines for its third runway after some, including British Airways, EasyJet and Ryanair, threatned to withdraw support if passenger charges are not kept the same or lowered after expansion.
Heathrow announced at the end of last year it had found options to trim £2.5bn off expansion, bringing the total cost to £14bn, including by phasing construction. It said the extra savings had made it "increasingly confident" it could meet "the affordability challenge".