Experts were expecting to see dozens of meteors an hour in some places as the shower approached its peak this morning.
The annual Orionid shower, so-called because it appears from the direction of the constellation Orion, is created when earth passes through trails of debris floating through space.
It is visible from almost anywhere in the world, because Orion - "the hunter" - is on a sight line very close to the equator, but the best viewing is found in rural areas away from light pollution.
Peak time for viewing the week-long shower, which is visible with the naked eye, was between 1am and dawn local time on 20 October, regardless of the viewer's location.
This is the point at which the viewer's location would be facing directly forwards on Earth's orbital path, effectively careering headfirst through space.
Some of the most intense activity was expected at 6am ET in America, or 11am in the UK, where daylight would obscure the spectacle.
The shooting stars which can be seen in the sky are caused when fragments of the comet– which typically range from pea-sized to the size of a grain of sand – burn up as they enter earth's atmosphere.
Halley's Comet leaves a fresh track of debris behind it as it passes earth every 76 years, and earth passes through the trail each October.
Some Twitter users reported seeing about 20 comets an hour, while others said cloud and fog had ruined the occasion.
One said: "Decided to wake up at 5 to watch the meteor shower. Saw about 6 meteors in 10 minutes. Gonna be a good day."
However, another user voiced the frustration of many by saying: "Every time a good meteor shower rolls around, it's always overcast or straight up raining. Lame."
Some videos have already found their way onto YouTube, with more likely to appear later as the shower finishes above the United States.