St Mary's Weather Forecast, Cornwall TR21 0

Today 18 Jul South West England

Mainly cloudy in the west at first with patchy rain gradually easing as it spreads eastwards. Brighter later, and in the east, with lengthy spells of sunshine for many in the afternoon. Feeling warm and muggy with light winds. Maximum Temperature 24C.

Tonight 18 Jul South West England

Some late sunshine for many before skies turn cloudier through the night with sea fog developing along the south coast. Mainly dry but feeling warm and muggy for all. Minimum Temperature 13C.

Sat 19 Jul South West England

A mixture of sunshine and showers, these heaviest and carrying the risk of thunderstorms and hail in the east. Sunny spells further west, before rain arrives in the southwest later. Maximum Temperature 23C.

Sun 20 Jul South West England

Further showers are expected on Sunday with heavy, thundery downpours. Drier and brighter from Monday although a few heavy showers are still possible. Feeling warm in sunny spells.

Mon 21 Jul South West England

Further showers are expected on Sunday with heavy, thundery downpours. Drier and brighter from Monday although a few heavy showers are still possible. Feeling warm in sunny spells.

Tue 22 Jul South West England

Further showers are expected on Sunday with heavy, thundery downpours. Drier and brighter from Monday although a few heavy showers are still possible. Feeling warm in sunny spells.

Wed 23 Jul South West England

Overall a rather more changeable pattern of weather through this period, compared to much of the summer thus far. Wednesday will likely see a continuation of heavy, perhaps thundery showers, although the focus may be more across the north and east by this stage. Thereafter, a general westerly or north-westerly regime looks to become established, with occasional weather systems moving in from the Atlantic. This means further rain or showers and breezy conditions at times, especially in the northwest. This will be interspersed with some drier, sunnier periods. Temperatures are expected to be close to or a little above average for most of the period. This broad pattern is likely to continue through to the end of July.

Thu 24 Jul South West England

Overall a rather more changeable pattern of weather through this period, compared to much of the summer thus far. Wednesday will likely see a continuation of heavy, perhaps thundery showers, although the focus may be more across the north and east by this stage. Thereafter, a general westerly or north-westerly regime looks to become established, with occasional weather systems moving in from the Atlantic. This means further rain or showers and breezy conditions at times, especially in the northwest. This will be interspersed with some drier, sunnier periods. Temperatures are expected to be close to or a little above average for most of the period. This broad pattern is likely to continue through to the end of July.

St Mary's Weather Forecast

Today 18 Jul South West England

Tonight 18 Jul South West England

Sat 19 Jul South West England

Sun 20 Jul South West England

Mon 21 Jul South West England

Tue 22 Jul South West England

Wed 23 Jul South West England

Thu 24 Jul South West England

Temperature Forecast Met Office

Temperature Real-Time

Predannack (Cornwall) Radar

National Satellite

National Synoptic

St Mary's Temperature Statistics

July Temperature

Scilly St Marys (1km)

Lowest 8 February, 2025

Average 2025

Highest 11 July, 2025

Lowest 4 June, 2025

Average June

Highest 27 June, 2025

Lowest 4 July, 2025

Average July

Highest 11 July, 2025

Climate (2020–Present)

Scilly St Marys (1km)

Average Low 2020–2025

Average 2020–2025

Average High 2020–2025