Darkness fell across the North West Cape about 11.29am AWST (1.29pm AEST) when the moon completely blocked the sun for a minute after temperatures dropped by five degrees suddenly.
Perth schoolgirl Georgie Gibbs said it felt eerie.
"It's surreal. It feels like a dream actually," she told AAP.
The eclipse lasts about three hours as the moon passes between the sun and earth as a partial then total eclipse, casting a 40km wide shadow over the World Heritage-listed Ningaloo reef region.
A bright solar corona that looks like a white halo visible to people in the path of totality, along with some stars and planets was eagerly anticipated.
As the partial eclipse started Lois Polatnick from Chicago described his excitement.
"The moon is taking a bite out of the sun as we enter the shadow of the moon," she said.
"We can see sun spots as we eagerly await totality.
"My favourite parts are the diamond ring and solar flares that become visible as we enter totality."
Detroit man Shane Varrti, who has seen five eclipses, said he had started to plan his trip a year ago.
"It's very exciting. All this effort has come to fruition," he said.
Astrophysicist Melanie Johnston-Hollitt has always wanted to experience a total solar eclipse and never been in the right place at the right time.
"To be able to see it from Australia makes it particularly special," she said.
Cruise passengers took in the event on a ship off Exmouth, while eclipse goers set up along the roadside along the route to the main viewing point at Cape Range National Park.
Prof Johnston-Hollitt said the eclipse would help people understand the structure of the solar system.
"We are on a rock, the earth, being orbited by another rock, the moon, both of which are orbiting a star, the sun, in the vastness of space," she said.
The air temperature is also likely to drop during totality and animals may change their behaviour.
Thursday's eclipse is considered rare because it's a hybrid eclipse that starts as an annular eclipse in the Indian Ocean before changing into a total eclipse near Exmouth.
The Perth Observatory website crashed as people took to the web to watch a live stream of the eclipse.
The observatory turned to Faecbook to provide an avenue to view stream the phenomenon.
"Thanks for visiting our website. You all crashed it," the observatory said.
By the time the eclipse reached its peak, the website was back up and running, though the link to the livestream continued to be down.
Exmouth, with a population of about 2800, has swollen with thousands of visitors keen to witness the eclipse, arriving by air and road.
A festival atmosphere has taken hold, with concerts and events at towns and cattle stations across the region.
Campsites have sprung up in front yards and on vacant blocks of land and the streets are bumper to bumper with 4WDs and camper vans.
Exmouth's Earlybird Cafe had a line of customers out the door on Thursday morning.
Owner Mandy Brendel said the influx of visitors had kept her and three staff busy in the lead-up to the eclipse.
"It's been absolutely amazing," she said while making coffee.
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