Updated each month, these experimental forecasts provide the probability that temperature and rainfall, averaged over a three-month period, will be above or below the climate norm for various regions.
Previously, such data cost an arm and a leg, afforded only by huge corporations.
For the UK, the predicted outlook to the end of July is that it is likely to be warmer than normal over most areas, but wetter than normal over the western parts of the country.
Mike Davey, manager of the Met Office’s seasonal prediction group, said: “These are very different from a daily weather forecast which gives information for a particular place and time: with seasonal forecasts we provide likelihoods for conditions averaged over a few months.”