West Australia was treated to a rare show last night as a meteor blazed across the sky between Perth and the Goldfields.

Perth Observatory received dozens of reports of blue, green and orange lights in the sky between Perth and Leonora and east to Kalgoorlie just before 8.30pm.

Experts say the fireball was probably a meteor -- about the size of a cricket ball -- burning up as it passed through Earth's atmosphere.

Perth Observatory astronomer Ralph Martin said the meteor was spotted about 8.25pm -- just before sunset -- as it hurtled in a south-to-north direction across the southern half of WA at a speed of about 20km per second.

Mr Martin said some callers reported seeing a "blueish flash'' as the meteor streaked across the sky. Most people only glimpsed the phenomenon for "two to three seconds.''

The Observatory received reports from Perth, through the Wheatbelt towns of Beacon, Bolgart and Toodyay, out to Kalgoorlie.

One man from Kalgoorlie rang to check what it was, thinking it could have been a safety flare set off in an emergency.

"It came over about 8.25pm,'' Mr Martin said. "People reported a bright blueish flash and then a streak coming out out of it, some people said they saw a trail of light.''

"It was twilight, there were no stars. Had it been dark, it would have been awfully bright.

"Because they travel so fast people will only see them for a couple of seconds.''

Mr Martin said WA probably experiences several meteor events a year, but because they are extremely quick they are not seen by many people.