"Actually, I do not believe," my driver says for about the fifth time that afternoon.

But many Indonesians do believe that rain shamans, or pawang hujan, possess a mystical faculty that enables them to redirect rain and they are in hot demand over the wet season, which usually stretches from November to March.

Wedding organisers often use their services: friends who married in Bali were told the day after their ceremony that a pawang hujan had been part of their package. (It didn't rain, apparently.)

In late October the committee chairman of the Tour De Linggarjati, an international cycling race through West Java, announced pawang hujan would be deployed at three locations to ensure the event ran smoothly.

And Bandung Football Club employed three pawang hujan, who meditated for three days without food, water or a shower, to ensure the February 13 match against Bali United was dry.

The rain has already stopped when we arrive at a lavish wedding at Segarra, a beach club in Ancol in northern Jakarta.

Weather spirits

The Bruno Mars' pop song Marry You is filling the balmy night, fairy lights twinkle on the lawn, white linen-covered tables groan with food and images of the happy couple beam from a huge screen. Clearly this is not an event to be trifled with by the weather spirits.

Muslimin Suparman, a wiry 67-year-old with closely cropped hair dyed a garish maroon, a batik shirt and an incongruous Sydney NSW cap, has been hired to keep the rain at bay.

"My name is Muslimin and I am Muslim," he tells us, flashing his perfect teeth.

According to the 2012 Pew Forum on Religion & Public Life, 69 per cent of Indonesian Muslims believe in sorcery and 38 per cent say they use religious healers.

Muslimin, or Pakde (Uncle) Mus, as he is better known, is from Java, where many people adhere to a religious tradition known as kejawen, which syncretises animistic, Islamic, Buddhist and Hindu beliefs.

His parents, grandparents and great-grandparents were followers of traditional Javanese beliefs.

"As a Javanese person, I routinely fast, every Mondays and Thursdays. But on certain Fridays – I use a Javanese calendar to mark these particular Fridays – I meditate from 1am to dawn. And at a certain time of the year, I fast for 40 days. There is one day within the 40 days where I do not only fast, but it is forbidden for me to talk and to sleep. These are some of the routines I have to do to maintain my skill."

Pakde Mus has been a pawang hujan since 1973. He says he can also heal people from mystical illnesses, a profession known as dukun in Indonesia.

Black magic

"The person may be attacked by black magic – perhaps he has done a bad thing against his friend so his friend sent black magic to him," Pakde Mus says. "Doctors cannot cure that kind of illness, people such as me can help such patients."

But today he is being paid to "move raining to the east, to the west, to the north, to the south or to the sea". It's peak season for pawang hujan, especially the weekends of course, and Pakde Mus charges from 1 million rupiah ($100) for a one to six-hour package, to 4 million rupiah, for a one to 24-hour package.

Events outside Ancol incur extra charges and Pakde Mus warns that attempts to haggle over the price can result in failure and rain. There is an old saying, apparently, that one can not negotiate with the supernatural.

The dark storm clouds gathering overhead appear menacing but Pakde Mus is relaxed as he puffs on sweet-scented kretek – cigarettes made from a blend of tobacco and cloves. The art of being a pawang hujan, he says, is to learn how to be close to God so that you can ask for it not to rain.

"Usually after I am contacted by the event organiser, I will meditate, I pray to Allah to help me prevent the rain from falling on the date the organiser said. That is on the Islamic side. I also adhere to the Javanese beliefs. Every area has a caretaker, a spiritual being. Nobody can see this being, because it is unseen. But people like me can talk to it. Basically, I instruct the being to hold the rain from pouring down."

Three days before an event, Pakde Mus abstains from sex with his wife. "If the area is cloudy I can't wash my face with water or wash my hands, but if it is sunny, no problem," he says.

Ancol, the part of North Jakarta where today's wedding is being held, is an area popular with wealthy Chinese Indonesians. If there is a big event here, organisers will sometimes hire rain masters from China as well as Java. This can be catastrophic: if the rain masters do not work together, Pakde Mus tells us, the clouds could be pushed into each other and open over the event.

Communing

"There always must be communication with Pak Muslimin, who has experience in this place," he says.

Pakde Mus' connection to Ancol goes back years. He once trained dolphins, sea lions, birds and honeybears at the amusement park Ancol Dreamland. After retiring in 2004 he set up a snack shop, but when that went bankrupt, he decided to become a full-time pawang hujan.

In March 2012, Indonesia's then leading opposition parties, the Indonesian Democratic Party of Struggle (PDIP) and the Great Indonesian Movement Party (Gerindra) announced Joko Widodo would be their candidate for Jakarta's gubernatorial elections.

"I was hired to handle the weather," Pakde Mus says. "Thank God things went well." (Joko Widodo was ultimately elected governor and then rose to become President of Indonesia two years later.)

In late December 2014, Pakde Mus was contacted by an event organiser a few days before an international jazz show in Ancol.

"So I did some rituals and thank God during the week when they were preparing stages, the sound system etc, the weather was good. There was no rain at all for a week. But a problem occurred right on D-Day. The rain poured down the first few minutes after the show began. But I wasn't scolded by the organiser because the tickets sold out and the park was packed with people. The organiser was happy. And the rain somehow stopped in the middle of the show."

Offerings

It's getting dark now and Pakde Mus needs to get ready. We clamber onto a roof above a parking lot of motorbikes. Pakde Mus has changed into a peci (Muslim cap) and long-sleeved top with the Indonesian flag sewn on one sleeve and a cloth badge with Monas, the national monument, on his chest.

Amid a jumble of broken and stacked wooden furniture he has set up a low red table. The air conditioner unit behind us is roaring. The table is cluttered with offerings: lavender incense from Thailand, five types of flowers, shot glasses filled with different-coloured liquids and two chicken eggs.

"Two because everything in life comes in pairs, like husband and wife, or male and female," Pakde Mus says. The incense is also pivotal.

"As in the real world, if you ask someone to help you have to pay him, so it is in the spiritual world. I ask the being to avoid rain from falling down, so I have to give it something back. In this case, I burn some incense. Incense is the being's food. In the past people used myrrh, nowadays we use incense. It loves incense and perfume. So I usually burn incense and spray perfume in a certain radius of the area where the event is going to be held. It is aimed at feeding the being."

We watch as Pakde Mus, utterly self-absorbed, prays and then points towards the dark heavens with sticks of incense and two beautifully patterned kris, Javanese daggers that are believed to possess magical powers.

"I raise up my kris to the air, directing at the cloud, then move my kris to the opposite direction of the venue, instructing the cloud to pour the rain somewhere else," Pakde Mus tells us before the ceremony.

I ask him if he still gets paid even if it rains. He assures me he does: "If people request a warranty that it won't rain for eight hours, I can't do that." All he can do, he says, is ask God.

But it didn't rain. When we leave, the bride is arriving at the venue, solemnly preceded by her bridesmaids. I wonder if she is aware of all the work that has gone into creating her perfect day.

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