Cornwall weather: Saturday 29 August, thundery rain and coastal gales

If you had big plans for the last Saturday of August, keep the waterproofs within reach. Cornwall opens the bank holiday weekend under heavy, persistent rain, and by the afternoon there is thunder in the mix and the threat of gales along the south coast. It is a properly unsettled spell, and the weather across Cornwall stays lively right through to midweek.

Today

An unsettled start, with heavy, persistent rain to get the day going. That rain turns thundery into the afternoon and arrives with strong, squally winds. Forecasters have flagged the risk of coastal gales in the south, so the south coast could catch the roughest of it. Things gradually clear eastwards as the day goes on. The maximum temperature is 21°C, mild enough on paper, though it will not feel that way when the squalls blow through.

Tonight

The showers hang on across the east of the region through the evening. Further west it turns drier, and clear spells start to develop as the night wears on. The minimum temperature drops to 14°C, the coolest air of the next few days.

Sunday

Sunday begins cloudy before sunny spells break through, but do not get too comfortable. Those bright moments soon give way to showers, and this time they turn heavy, with thunder and hail through the afternoon and evening. Temperatures sit close to normal for the time of year and the maximum climbs to 24°C, the warmest day of the weekend even as the sky throws everything at it.

Bank holiday Monday to Wednesday

The unsettled theme carries on into the new week. Expect showers throughout, some of them locally heavy and thundery. It stays warm to begin with, then turns fresher as the winds swing round to a westerly and strengthen from Monday. So the weekend does not so much end as change character, trading the warm, thundery air for something brisker off the Atlantic.