CBH is edging closer to its revised harvest estimate of receiving 15.5 million tonnes of grain after reaching 15.3mt just prior to Christmas.
Late last week the Geraldton zone had received 3.28mt, Kwinana 6.79mt, Albany 2.65mt and Esperance 2.55mt.
Predictions from the start of harvest were for Geraldton to deliver 2.8-3mt, Kwinana 6.5-8mt, Albany 3.2mt and Esperance 2.5mt.
Hot and gusty conditions caused several shires to declare a harvest ban last week and light rain also delayed growers in some areas.
The Bureau of Meteorology recorded falls of three millimetres at Tardun Hill in the Central West, 3mm at Seven Oaks near Westonia, 3mm at Wandering, 2mm at Dumbleyung and 1mm at Wyalkatchem.
CBH Kwinana zone manager Gavin Bignell said in general tonnage was starting to slow but some areas were still under pressure.
"Sites from Moora through to Wongan Hills are still under a fair bit of pressure and Brookton through to Dale and Narrakine and the Williams area will still be very busy into the new year," he said.
The CBH Metro Grain Centre was also under pressure as some services were closed during parts of harvest to keep grain moving through the network.
So far almost 6.8mt of grain have flowed into the Kwinana zone, with Mr Bignell predicting that will surpass 7mt by the new year.
"We are still taking 100,000-150,000t per day in the zone and, weather permitting, we will be done by the new year," he said.
"Overall the quality has been better than expected from the frost and the tonnages are over and above expectations."
He said harvest around Esperance and Geraldton was nearly finished, and the only grain still coming in was from silos and bags that had been stored on farm during the busy period.
The Albany zone will still be harvesting well into January due to the delayed start from cooler conditions during spring.
Mr Bignell said heavier rain on December 10-11 had not yet affected grain quality, despite some areas receiving more than 100mm in 48 hours but falling numbers and grain re-sprouting was a concern.
Grain still in the paddock could also be damaged by Cyclone Yvette, which could bring showers into the South West.
"There's been no quality issues that we have seen as yet from the earlier rain as the zone dried out quickly, but the cyclones brewing could see some issues in terms of quality for grain still needing to be harvested," Mr Bignell said.