With no rain, Tonga is still blanketed in ash, which some on the ground have described as being like "thick black snow".
Photo: Consulate of the Kingdom of Tonga
Katie Greenwood, from the International Federation of the Red Cross, says the ash keeps circulating in the air, causing breathing issues.
It is also affecting ships going to the outer islands - getting into their engine systems.
Greenwood, who is currently in Fiji, told Morning Report without rain, the ash hasn't been able to settle.
"That's one of the main issues, is this thick blanketing of ash."
"They (the Red Cross team in Tonga) really think it's going to take more than a month just for the initial cleanup itself. Apart from that they are concerned about the drinking water which they have been continuously distributing since the emergency began."
Planning for short, medium and long term responses is currently underway, she said.
Additional support hasn't been requested.
"One of the great things about the local reach of Red Cross and the locally led action is that there is a fantastic and experienced team there on the ground who have been doing the work that the need to do since day one."
For some specialist areas like water and sanitation, Red Cross may need people who can provide technical advice to go and support the team.
"So, we will be waiting to hear what the governments plans are around whether they want to allow people to come in. Of course we would never be wanting to circumvent any of the restrictions they've got in place. Tonga's done a wonderful job of keeping Covid at bay, we don't want to swap one disaster for another."
It isn't clear yet how crops have been impacted by the ash.
Volcanologist professor Tom Wilson from Canterbury University says the images coming out of Tongatapu and a few other others suggest that there is a couple of centimetres of ashfall.
"Usually what that means in a tropical context is the ash will adhere to a lot of the vegetation, it could cause reduction in photosynthesis and even chemical burns to the vegetation."
He told First Up if the ash isn't cleared by rainfall or other means then it can be potentially destructive to the plant.
"This big concern for vegetation is what is the stage of development or the growth stage of the particular crop of vegetation."
Volcanic ash is usually a fine grain, which can interrupt pollination.
If soil is tilled, there's a chance the ash can be mixed through.
"It's likely in the medium term - weeks to months - that it will have a fertilising effect so there will be minerals and other bits and pieces in the ash that will be positive to the soil.
"The challenge is in the short term they're quite detrimental, they have quite a negative effect."
"It could cause reduction in photosynthesis and even chemical burns to the vegetation" - Volcanologist professor Tom Wilson