On this basis, Statistics New Zealand said exports may be down as much as 19 per cent on what might have been expected.
Overall, New Zealand's exports were down 2 per cent on the same period last year, but down 3 per cent based on how much exports might have been expected to grow.
The figures cover the period from January 27 to February 23 and represent something of a rough guess of the impact of disruptions of trade to China.
While Statistics New Zealand made a series of cautions about inferences from the numbers, it acknowledged the changes in recent weeks were significant.
"These are out-of-the-ordinary movements," Richard Evans, Statistics New Zealand's general manager of economic and environmental insights, said.
Forestry exports in the period to China were $180 million, down from around $250m in the same period in 2019.
Meat exports to China were around $170m in the period in 2020, down from around $280m in the same period in 2019.
By weight, meat exports have fallen by half, from around 40,000 tonnes during the same period in 2019, to around 20,000 tonnes this year.
The official figures for New Zealand's exports in February will be released on March 25.
Seafood exports in the period in 2020 were around $30m, down from $70m in the same period in 2019, export growth for seafood had been strong later in 2019.
Stats NZ visitor figures released on Friday showed the number of those from China plunged 30 per cent in the four weeks to February 9 to 44,000. Tourism New Zealand estimates the hit to spending by Chinese during the peak January to March period could range from $250m to $500m.
BNZ senior economist Craig Ebert said while the export figures were useful, it was too early to draw any conclusions about the impact of the virus.
"That's not to say these don't look that bad, because there's clearly some weakness to look for in the data, but I just don't think there can be any definitive judgment on it, at this point."
Monthly export figures were volatile, and the changes may not only reflect the impact of Covid-19, Ebert said, with forestry exports likely to be hit by increased supply from Europe, anyway.
"We can believe there's some serious disruption going on with not only exports, but also imports as well ... I just think it's too partial and early to draw any conclusions from this data."