Cornwall weather: Wednesday 23 September, grass frost after the sun

The week is about to swing from grey to bright, but the return of the sun comes with a catch after dark. Cornwall starts Wednesday under cloud with a little light rain around, then clears from the west into sunny spells, before a cold, still night drops temperatures low enough for a grass frost in places. Here is how the Cornwall weather looks through to the weekend.

Today

It is a cloudy, mostly dry start across the region, with a chance of some rain over the north and west of Cornwall through the morning. The skies then clear from the west during the afternoon, opening up plenty of sunny spells to round off the day. Temperatures sit around average for late September, reaching a high of about 21°C.

Tonight

This is where it gets interesting. The night stays dry with plenty of clear spells and light winds, and with nothing to hold the day’s warmth in, temperatures fall away fast. Rural and sheltered spots could drop into low single figures, as low as 3°C, and a grass frost is likely in places. It is the first real frost signal of the season, so it is worth covering anything tender in the garden before dark.

Thursday

Thursday keeps things bright with hazy sunny spells for much of the day and dry conditions for everyone. Winds stay light and temperatures nudge a little higher, sitting around or just above average, with a high near 22°C. It is the warmest and calmest day of this run.

Friday to Sunday

The settled spell does not last. Rain moves in from the west on Friday and pushes eastwards through the day, turning brighter with a few showers later on, though temperatures hold around average. That unsettled theme then carries on across the weekend, with further rain advancing eastwards. After a bright, frosty stretch in the middle of the week, it is a wetter and more changeable end to it.