The Disasters Emergency Committee's Cyclone Idai appeal has raised £27m in its first two weeks.
The sum includes £4m of matched funding from the UK government.
Asked how the amount raised after two weeks compared with other appeals, a DEC spokeswoman said: "We don’t supply those numbers. Each appeal is open for six months, so we wouldn’t be comparing like with like, especially given that major donors make contributions at different times."
In 2017 the DEC reported that its East Africa Crisis Appeal raised £50m in its first three weeks, and its Syria Crisis Appeal generated £10.3m in roughly the same period after it was launched in 2013.
The 2010 Haitian Earthquake Appeal raised £50m in just under two weeks and the 2014 Ebola Crisis Appeal hit £20m in three months.
The latest appeal was launched to help survivors of last month’s cyclone, which killed more than 750 people and left more than three million people in need of humanitarian assistance in Mozambique, Malawi and Zimbabwe.
A DEC statement said floodwaters had receded but survivors faced the secondary threat of disease.
The statement added: "DEC members are rushing to deliver clean water, toilets and hand-washing facilities to prevent cholera as the number of cases is reported to have risen to 1,428 in Mozambique."