Britain to sizzle at 30C as jet-stream finally moves north As we move towards Friday there's a chance of it becoming more unsettled and a chance of showers and rain across the south. There's a chance of showers on Friday. The reason for this more pleasant weather is that the jet stream has moved further north and in the south we are getting more of the high pressure, at least for the time being. But it doesn't look as though the dry clear spells are going to stay around indefinitely. She said that it was too early to say how July had fared compared to previous years, following the wettest April to June since records began. But it was definitely soggy. She said: "From July 1 to July 15 we had 92 per cent of the average rainfall for the month."