"It helps people see that we're not a cult, and we're not mad. Well, not too mad."
The ceremony of Alban Arthan, which is attended by at least 200 people every year, commemorates the symbolic death of the sun and the rebirth of the Mabon, the Celtic Son of the Light, which heralds the coming of a new season.
Ms Meekings-Stewart says a part of the ceremony is dedicated to mourning the sun, which is symbolic of the "mourning" in the human psyche when winter arrives - which Kiwis are all too familiar with.
"It's reconnecting people with nature - the cycle of the seasons is reflected in our own bodies and our lives," says Ms Meekings-Stewart, who has been a practising druid for 12 years.
"In winter, we experience depression and don't want to go anywhere. It can be frightening, and it was the same with our Northern ancestors. They didn't know when the sun would be back and, if the sun didn't come back, they'd starve.
"When we celebrate the rebirth of the light, it symbolises the return of hope for each of us.
"We might be feeling dark and depressed and horrid, but it's okay, because the days are getting longer and, hopefully, warmer."
Ms Meekings-Stewart says the philosophy of druidism, connecting with the spirit of the land, is not at all dissimilar to the deep spiritual connection Maori have with nature.
"It also fits in with Matariki. Hope was restored when Matariki [the Pleiades] appeared in the sky - as they knew the weather was going to get warmer," she says.
At today's ceremony, karanga will be performed by the Grove of the Summer Stars' te reo speakers to herald the death of the sun and birth of the light.
Mrs Meekings-Stewart, a former documentary film maker, was first attracted to druidism when she attended a seminar ran by chief druid of the Order of Bards, Ovates and Druids Philip Carr-Gomm.
She now leads weekly meetings of the Grove of the Summer Stars, whose members are based in Wellington, Wairarapa and Kapiti, from her farm in Pukerua Bay.
"What I love most about druidism is that its different for everyone," she says.
"We're not exclusive - we have Christian Druids, Pagan Druids, Jewish Druids. If you're open to experiencing the spirit in nature, how you express it is up to you."
Today's Winter Solstice Celebration will be held at 4.30pm at Stonehenge Aotearoa, beginning at sunset.