The weather may prove to be a party pooper for tonight's rare full lunar eclipse.
Starting at 6pm, as the moon rises it will move into the shadow of the Earth cast by the sun. At full eclipse the moon becomes blood red in colour.
Astronomer Ron Fisher said although lunar eclipses were not particularly unusual events, what made this eclipse rare was its timing in the early evening.
"You usually have to be quite dedicated to see a lunar eclipse, because they tend to happen in the middle of the night. And the process of the moon going into eclipse is slow - about two hours - so then you're looking at the early hours of the morning for a full eclipse."
Tonight's lunar eclipse will be at its height at about 7.45pm, although Mr Fisher said watching the moon slide into darkness will make good viewing from 7pm onwards.
He said moon gazers should make sure they have as clear and unobstructed a view of the horizon as they can, although by the time the moon is in total eclipse it should be quite high in the sky.
However, Daniel Corbett from the MetService said today's weather forecast for Wanganui was for cloud with late showers.
"For those hoping to catch a glimpse of the lunar eclipse, cloud will make viewing difficult - except perhaps for those living in eastern parts of the North Island."
Mr Fisher said despite that, there was a good chance that moon gazers may catch a glimpse of the blood-red moon during a break in the clouds.
He will run a moon-gazing event tonight at Churton School, Burmah St, Aramoho.
From 6.30pm, local artist Julian Priest will give a presentation on launching a real satellite into space.
Then telescopes and binoculars will be available to look at the eclipse, although Mr Fisher said the eclipse could be seen with the naked eye.
The Ward Observatory in St Hill St will also be open tonight from 6pm for moon gazing. Entry is by gold coin donation.
Observatory president Ross Skilton recommended people turn their eyes skyward between 7pm and 8.25pm.
"At that point [the moon] should be a nice, deep red," he said.
Both events are open to the public, and will go ahead regardless of the weather.
The next lunar eclipse visible in New Zealand is in October.