Filmmaker's must-have tech - Met Office Weather App -

http://www.metoffice.gov.uk/services/public/free/mobile/iphone 

Yes that's right. I'm extolling the virtues of a weather app. I just love it so hard. And it's a great tool for call sheets and planning shooting. Time to salivate 2nd ADs...

The app gives a 5 day forecast just like the Met Office website (which most filmmakers use in their canon of weather forecasts anyway) and then you can neatly navigate to the next 24 hours, with hourly changes including chance of rain, windspeed, visibility, temperature etc. All the good stuff. It has sunrise and sunset times too and severe weather warnings to add into your unit notes.

It defaults to your local area and of course you can add other locations if you want to.

There's also a map feature that shows rain-bands, again with hourly updates that you can scroll through and see when the rain is going to hit you and move off again.

It's slick, quick, easy to use and super-informative. But, of course, if you're in the back-end of nowhere in the pouring rain with no internet signal it's less useful than a chocolate teapot - at least you can eat that. Time to call a forecaster...