Weather
Weather satellite images
- Visible Spectrum - daylight only - Updated once per day at about 13:30 GMT with the 12:00 GMT picture
- Infrared Spectrum - 24 hour - Updated with pictures taken at 00:00, 06:00, 12:00 and 18:00 GMT and uploaded appoximately 90 minutes later.
These images come from satellites which remain above a fixed point on the Earth (ie. they are “geostationary”). The visible picture shows a black and white image similar to what a person sitting on the satellite would see. The infrared picture shows the same view but looking at a part of the spectrum which our eyes do not detect.
The infrared pictures allow us to measure the temperature of the cloud tops, which can be used to determine their height. The whiter clouds are colder than the greyer clouds in this image. Infrared images can be recorded 24 hours a day. Visible pictures can only be made during daylight hours.