Stargazing Forecast: Will You Have Clear Skies Tonight?

“Everybody talks about the weather, but nobody does anything about it” — together with astronomers. We can, nonetheless, at the least get the knowledge we have to resolve if the skies can be adequate to arrange a telescope at a darkish website—and even within the yard.

Astronomy Stargazing Forecast Sites & Apps

The first place many astronomers flip for observing forecasts is Attila Danko’s Clear Sky Charts.  It assembles knowledge from the Canadian Meteorological Centre right into a stargazing forecast spanning 180 hours.  A chart for a specific location makes use of rows of coloured squares to point cloud cowl, transparency, and seeing. There are charts for hundreds of places within the U.S. and Canada, together with the websites of main star events.

Clear Sky Charts
In Clear Sky Charts, darker blue squares point out higher situations relating to cloud cowl, seeing, and transparency.

A considerably newer app, Egg Moon Studio’s Scope Nights, has turn into a favourite of newbie astronomers. Scope Nights works in related trend to Clear Sky Charts however compiles knowledge from the U.S. National Oceanic and Atmospheric Administration (NOAA), the European numerical forecast mannequin, and different sources to offer worldwide stargazing forecasts. Scope Nights is gorgeous, and its easy graphics make stargazing situations clear at a look. Both day by day and hourly forecasts can be found. The app additionally shows gentle air pollution situations on a map.

ScopeNights screen
Scope Nights’ fundamental display shows the astronomy forecast for six nights.

Astrospheric, which payments itself as “advanced weather forecasting for North American astronomers,” is just like Clear Sky Charts, however provides significantly extra data. In addition to the fundamental forecast, there are satellite tv for pc photographs, an prolonged cloud forecast, and lunar data, together with section and rise/set instances.  Like Clear Sky Charts, Astrospheric makes use of coloured squares to point situations, however they’re additionally summarized if you mouseover: “cloud cover 82%,” “transparency, cloudy,” “seeing average.”

Astrospheric screenshot
A stargazing forecast on the Astrospheric app exhibits related knowledge to Clear Sky Charts, however with extra data, together with a satellite tv for pc picture of cloud cowl.

All three of those web sites are additionally accessible as apps for each iOS and Android gadgets.

General Weather Forecast

Although not aimed particularly at astronomers, main climate providers supply apps that show situations and forecasts. While most of those do have some astronomy data, and a few even characteristic astronomy pages, astronomy knowledge are normally restricted to fundamentals like dawn, moonrise, and perhaps an occasional characteristic on particular occasions like meteor showers.

The downside with these apps is their inconvenience on a darkish observing subject. All require loads of scrolling, and getting particulars typically requires studying small textual content. Most are additionally advertising-heavy.

Even so, I’ve used each the webpages and apps of The Weather Channel, Wunderground, and Accuweather with nice success throughout darkish sky expeditions. Among their most precious options are their radar and satellite tv for pc photographs that make it simple to see when unhealthy climate is coming.

DIY Stargazing Forecast

Being capable of put collectively an correct climate forecast requires not simply high-tech climate devices, however years of coaching and expertise. Nevertheless, by checking a couple of indicators it’s greater than doable to get an concept of the evening’s stargazing climate.


Clouds, in addition to blocking the sky, are the first technique of predicting climate with no forecast. More particularly, cloud layers transferring in several instructions point out unhealthy climate on the way. There’s an outdated saying about “mares’ tails” (cirrus clouds) and “mackerel scales” (altocumulus clouds): “Mackerel scales and mare’s tails make lofty ships carry low sails.”  It’s true these clouds typically seem prematurely of rain. If each are seen, unhealthy climate will arrive inside 36 hours.

Mares' tails cirrus clouds
“Mares’ tails” cirrus clouds
James St. John / CC BY 2.0

Keep a pointy eye out for “towers” of cumulus clouds. Patches of cumulus clouds are widespread on heat afternoons, however towering formations (known as cumulonimbus) point out the opportunity of extreme climate.


Rings across the Moon or (much less ceaselessly) the Sun are produced by ice crystals within the higher environment, sometimes in high-altitude cirrus clouds, and may imply that rain is on the way.


Wind is a much less correct indicator of storms however continues to be helpful. Easterly or southeasterly winds typically presage rain. Not positive of wind path? The outdated routine of sticking an index finger in your mouth and holding it as much as the wind truly works. The facet of your finger towards wind movement will really feel cooler.

Whether your forecast supply is an astronomy climate app, an internet site, or simply an index finger, listening to climate will make observing a much less irritating expertise. Who needs to disregard the climate, haul a ton of kit to a darkish website, and spend the night underneath clouds?

Alphabetical List of Forecasts:

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