Published: May 18, 2012
Updated: May 3, 2016
One of the necessary tools a night (or landscape) photographer must have in their tool bag is a decent weather forecasting tool. Though I’ve been known to ignore the forecast for some events, like an Annular Solar Eclipse, I definitely am more inclined to go where the weather is clearer (Nevada) than where it will be cloudy (Crescent City, CA).
A forecast like this despite how detailed it seems to be is all but useless to me:

Weather.com forecast
This is the hourly forecast. The “daily forecast” is less helpful. How partly is partly cloudy? And how mostly is mostly cloudly? Other sites sometimes just say “sunny” during the day and give no idea what night will be like. Compare the above with the Weather.gov forecast from NOAA.
NOAA to the Rescue (no Ark)
Fortunately the US National Weather Service provides a nicely detailed “click point” forecast with charts of the hour-by-hour conditions.

Weather.gov oh yeah.
There is quite a lot to take in here but it’s all good stuff. The “partly cloudy” at 7PM shows as 72% cloudy (Sky Cover) on weather.gov. Not only are the forecasts different, but I get more useful numbers. It looks like the wind will be very gusty during parts of the day. But the humidity won’t be so severe that dew will form. If it weren’t for the mostly cloudy skies, night photography might work out ok.
Where do you find this great tool. Start here: http://weather.gov
Once you get to the forecast, look for a small graphic on the right under “Additional Resources”. But that, my friend, is where the good stuff is. Before you rush off on the hourly thing, though, take a look at the little map window.

Weather.gov forecast area highlighed in green.
You can get a forecast for any specific area by clicking on the map! So, for example clicking on the summit of Mission Peak (just off the screen to the north) may give you a significantly different forecast – one that is adjusted for the difference caused by altitude.
Do remember that these are “forecasts” not actualities, so be prepared for whatever may happen.
Wunderground Classic
I used to use Weather Underground. Then they changed it so that the good stuff was only in “Classic”. But really, no need to use it at all any more.
May the wind not be at your back or in your face, may the road not be muddied by rain and may the clouds gather only when you really want them i.e. at sunrise and sunset.