Wales Weather Forecast Brings 25C Sun Then Thunderstorms 2026

key points?

• The weather forecast for Wales predicts sunshine and a temperature reaching 25 degrees Celsius on both Monday and Tuesday.
• Any patches of fog seen on Monday morning will clear fast.
• There could be a strong easterly wind on Monday afternoon close to the south coast of Wales.
• The night on Monday will be dry with temperatures around 10 degrees Celsius.
• Rain showers are likely to affect some southern parts of Wales late on Tuesday due to increasing humidity levels.
• Another low-pressure system moving from the south west is forecast to cause more unsettled weather conditions from Wednesday.
• Severe showers accompanied by thunderstorms could occur between Wednesday and Friday.
• Temperature levels are forecast to remain slightly higher than average throughout the week, but with increasing humidity levels.

Wales (Wales Times) August 24, 2026 — Wales is set for a largely warm and sunny start to the week, with temperatures reaching 25°C on Monday and Tuesday, before weather conditions turn increasingly unsettled and bring the prospect of heavy rain and thunderstorms from Wednesday.

The Wales weather forecast published by Wales247 says fog patches present during Monday morning should soon clear, allowing sunny conditions to develop across the country. The report adds that the sunshine is likely to become hazier later in the afternoon, while an easterly breeze develops near the south coast.

Wales247’s published forecast does not display an individual author in the available article text. The outlet reports that Monday will feel pleasantly warm, with a maximum temperature of 25°C forecast across Wales.

How will Wales weather develop on Monday?

Monday is expected to begin with localised fog, according to Wales247’s report. However, the forecast indicates that these patches should clear relatively quickly, leaving a fine day with lengthy spells of sunshine in many areas.

The report states that sunshine will turn increasingly hazy as the afternoon progresses. This means bright conditions may continue, although cloud or high-level haze could reduce the clarity of the sunshine later in the day. Wales247 also reports that a fairly brisk easterly breeze is expected to develop towards the south coast.

A maximum temperature of 25°C is forecast. The expected warmth, combined with dry and sunny conditions, marks a settled start to the working week for much of Wales.

What is forecast for Monday evening and overnight?

Wales247 reports that the fine weather should continue into Monday evening. The forecast indicates that Wales will then have a dry night with lengthy clear spells.

Conditions are expected to be breezier over higher ground, including hill areas. Despite the clear skies, the night is not expected to be as cold as some recent nights, according to the report. Temperatures are forecast to fall to a minimum of around 10°C.

The difference between daytime and overnight temperatures means people travelling early or late may experience cooler conditions, particularly in exposed rural and upland locations. The forecast itself does not identify any weather warnings for Monday night.

Will Tuesday remain warm and dry in Wales?

Tuesday is expected to continue the warm pattern, with Wales247 reporting that much of Wales should remain mostly dry and see spells of warm sunshine. Temperatures are again forecast to reach 25°C.

The outlook becomes less certain later in the day. Wales247 says there is a chance of a few showers drifting north from the south during the late afternoon. The report links this change to increasingly humid conditions.

The forecast does not state that all parts of Wales will receive rain on Tuesday. Instead, it identifies the possibility of some showers arriving from the south as the air becomes more humid.

When are heavy rain and thunderstorms expected?

The more significant change is forecast from Wednesday, when an area of low pressure moves in from the south-west. According to Wales247, this will make conditions more unsettled across the country.

Heavy downpours and thunderstorms are likely to be possible on each day from Wednesday to Friday, the report says. While the forecast identifies a period of three days when thunderstorms may occur, it does not specify individual counties, exact timings or the locations most likely to see the heaviest rain.

People should therefore distinguish between the general Wales-wide outlook and conditions in a specific town or city. Rainfall and thunderstorms can vary considerably by location, particularly during unsettled summer weather. The published report advises through its forecast that conditions will change from the settled start of the week to wetter and more humid weather in the second half.

Will temperatures fall when the weather turns unsettled?

Wales247 reports that temperatures are expected to remain slightly above average between Wednesday and Friday, despite the arrival of low pressure, heavy downpours and the chance of thunderstorms.

Humidity is also forecast to continue increasing through the latter part of the week. This could make conditions feel warmer or closer than the temperature alone suggests, especially before showers or thunderstorms develop.

The forecast therefore indicates a shift in the type of weather rather than an immediate move to cooler conditions: sunshine and mainly dry weather early in the week are expected to give way to a more humid, changeable and potentially stormy pattern.

What should people in Wales monitor this week?

The available Wales247 forecast sets out broad conditions rather than local impacts. People with travel, outdoor work, events or journeys planned from Wednesday onward may need to monitor updated local forecasts as the unsettled period approaches.

The reported risk of heavy downpours and thunderstorms is most relevant from Wednesday to Friday. Weather conditions can change quickly during convective showers, so regional updates may provide more precise information on rainfall timing and the areas most affected closer to the day. This is a general consequence of the forecast pattern described by Wales247, rather than a warning issued in the report.

What is the background to the Wales weather forecast?

The forecast describes a transition from a warm, settled spell to more unstable weather as low pressure approaches Wales from the south-west. Early-week conditions are expected to feature sunshine, dry weather and highs of 25°C, while the second half of the week is expected to bring greater humidity and a risk of heavy downpours and thunderstorms.

Wales247 attributes the outlook to the Met Office forecast, reporting that the developing low-pressure system is the expected driver of the change from Wednesday. The available article text does not provide weather-warning details, a named meteorologist, or a location-by-location rainfall breakdown.

How could the forecast affect people in Wales?

The warm and largely dry conditions forecast for Monday and much of Tuesday may support outdoor travel, work and activities, although cooler overnight temperatures and breezier hill areas could affect those out early or late.

From Wednesday to Friday, the prospect of heavy rain and thunderstorms could affect people travelling, working outside or attending outdoor activities, particularly if local conditions deteriorate rapidly. The forecast does not confirm where storms will occur, so the likely effect will depend on later local updates and the development of the approaching low-pressure system.