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When was the last time the UK reached 30°C in May?

With temperatures rising in the coming days and the likelihood of figures in excess of 30°C over the weekend and into the start of next week, we take a look at how often this threshold is reached in May and what's behind the figures.

While recent years have brought increasingly warm springs, a look at long-term records shows that reaching this daily 30°C threshold before June is still uncommon.

It's important to emphasise that most years do not see 30°C reached until June or later. For example, the first 30°C of the year occurred in June in both 2024 (25 June) and 2025 (19 June), while in some cooler or more unsettled years the threshold has not been reached until July or even August. This variability highlights how unusual it is for May to deliver true summer heat.

How rare is 30°C in May?

The most recent occurrence of temperatures reaching at least 30°C in May dates back to May 2012, when the threshold was met on 25 May. Prior to that, there were similarly high temperatures reported in May 2010 (23 May) and May 2005 (27 May), demonstrating that while uncommon, summer-like heat in May is not unprecedented in the UK climate.

Looking further back into the historical record, occurrences of 30°C or above in May are scattered and infrequent. This dataset (back to 1900) shows only a handful of years in which the 30°C mark was reached during May, reinforcing the idea that such events require a specific combination of conditions to align.

Among the earliest instances in the observational record are May 1944 (29 May), May 1945 (12 May), May 1947 (29 May), and May 1953 (25 May). These dates illustrate that early-season warm spells have occurred intermittently across the 20th century.

Overall, the pattern is clear: May 30°C events are sporadic rather than regular, typically separated by many years.

The hottest May days on record

While reaching 30°C in May is rare, the UK has experienced some high temperatures during the month. Records of the hottest May days provide further insight into how marked late spring heat can become when conditions align.

The highest temperatures recorded in May is 32.8°C, with several notable occurrences. These include readings at Camden Square and Greenwich in Greater London during May 1922, as well as across parts of southeast England including Tunbridge Wells and Horsham during late May 1944.

Other significant hot days include temperatures of around 32.2°C recorded at Camden Square on 31 May 1947, and 31.7°C recorded at Heathrow and Farnham on 25 May 1953. Most of these highest temperatures are concentrated in southern and southeastern England, where proximity to continental Europe and generally lower cloud cover increases the likelihood of warmth during settled conditions.

Why does May heat occur?

For the UK to reach 30°C in May, a number of atmospheric factors typically need to align. Persistent high pressure over or near the UK is often a key feature, allowing for prolonged sunshine and light winds. This setup can enable warm or very warm air to be drawn northwards from continental Europe.

Longer daylight hours also play a role. By late May, the UK is approaching the summer solstice, meaning solar input is already strong. Under clear skies, this can allow temperatures to rise quickly, especially when combined with dry ground conditions which limit evaporative cooling.

However, despite these favourable factors, the position of the jet stream and the variability of Atlantic weather systems often prevent such setups from becoming established in May. This is one of the primary reasons why 30°C is more commonly reached in June, July, or August.

A changing climate context

While the historical record shows that May heat has always been possible, there is growing interest in how climate change may influence the frequency and intensity of such spring's warm spells.

Recent decades have seen an increasing number of warm springs in the UK according to overall mean temperature. The three warmest springs on record have all occurred since 2017 in a series which dates back to 1884.

So, while the daily threshold of 30°C in May remains an infrequent occurrence, the temperatures experienced in spring overall have shown a rising trend.

Due to the UK's variable climate, individual years and seasons will continue to differ markedly. Cool or unsettled springs can still delay the first 30°C daily reading well into summer, as seen in several recent years.

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metoffice.gov.uk

u/Met-Office — 2 days ago

▲ 8 r/UKWeather+1 crossposts

Deep Dive: How warm will it get for the bank holiday weekend?

A marked change in the weather pattern is set to bring increasingly warm and settled conditions across the UK as we head towards the bank holiday weekend.

After a notably cool and changeable spell through much of May so far, temperatures are set to rise steadily, with many areas enjoying drier, sunnier weather by the end of the week.

For most people, the key message is straightforward: conditions are becoming more settled and significantly warmer than recent days. While there are still some finer details and uncertainties to consider, especially later in the weekend, the overall trend is towards more favourable weather for outdoor plans.

From unsettled to more settled conditions

At the start of the period, the UK remains under the influence of low-pressure to the northwest. This brings a continuation of showery conditions, particularly across northern and western areas. These showers are associated with a returning polar maritime air mass, which originates from colder regions such as Greenland and Canada before travelling across the Atlantic.

As this air moves over relatively warm ocean waters, it becomes increasingly unstable, picking up moisture and producing frequent showers, along with occasional heavier downpours or thunderstorms. This explains the unsettled feel early in the week, despite a gradual rise in temperatures compared to the previous northerly airflow.

As the week progresses, higher pressure begins to build from the south. This pushes the jet stream further north and gradually reduces the influence of weather fronts over much of the UK. While northern areas may still see some rain at times, southern and central regions will increasingly experience drier and brighter conditions.

Why it is turning warmer

Although winds are expected to turn more southerly by the end of the week, the rise in temperatures is not primarily due to hot air being transported directly from southern Europe or North Africa.

Instead, the main driver of the warming trend is the development of high pressure over and near the UK. As this high-pressure strengthens, it causes sinking air in the atmosphere. This descending air is compressed as it moves downward, leading to warming through a process known as adiabatic compression.

In simple terms, as air is compressed, its temperature increases. This process can significantly raise temperatures at the surface, even when the original air mass is not especially warm. In this case, much of the air over the UK still originates from the Atlantic, but it becomes warmer as it descends under high pressure.

This mechanism is a common feature of warmer spells in the UK and is often more important than the transport of heat from lower latitudes.

Temperatures on the rise

By Thursday, southern parts of the UK could reach the mid-20s, with 24°C possible in the southeast. Northern areas remain a little cooler, though still warmer than earlier in the week.

The most significant rise is expected by Friday, when many parts of England and Wales could see temperatures widely in the mid to high 20s. The highest values are likely in eastern and southeastern areas, while Scotland and Northern Ireland will generally be cooler, particularly in the northwest.

How hot could it get?

By Saturday, temperatures are likely to peak further, with 30°C possible in the southeast under the most favourable conditions. There is also a chance that temperatures could reach 30°C on Sunday, particularly in sheltered and sunny locations.

However, there is greater uncertainty at this stage. While the air mass itself has the potential to support higher temperatures, the development of showers or thunderstorms could limit how warm it feels in some places. Areas that remain dry and sunny are most likely to experience the highest temperatures.

In climatological terms, temperatures in the upper 20s during May are not unusual, occurring every few years. However, reaching 30°C is less common and only happens in a small number of years.

A risk of showers and thunderstorms

One of the key uncertainties for the weekend is the potential for showers and thunderstorms to develop, particularly from Friday night into Saturday.

This is linked to an approaching upper-level trough, which introduces instability into the atmosphere. At the same time, increasing warmth and humidity near the surface provide energy for convective activity.

Where these showers develop, they could be locally heavy and may bring cloud cover that suppresses temperatures. However, they are likely to be scattered in nature, meaning that some areas could remain dry and very warm.

Warm nights developing

Another notable aspect of the forecast is the rise in overnight temperatures. After a spell of chilly nights, minimum temperatures are expected to increase significantly.

By the weekend, some urban areas could see overnight temperatures remaining in the mid to high teens, with the potential for very mild or warm nights in places. Under certain conditions, this could approach record levels for May, although this will depend on local factors such as cloud cover and wind.

Outlook for the rest of the weekend

As we move into Sunday and bank holiday Monday, high pressure is expected to re-establish itself across the UK. This should bring a return to more settled conditions for many areas, with plenty of dry weather and sunshine.

The main uncertainty relates to how much of the warm air remains in place. Small shifts in the position of the high-pressure system could make a significant difference to temperatures, particularly in the south.

In some scenarios, temperatures remain in the mid to high 20s, while in others they drop back closer to average values. Despite this variation, the overall signal points towards largely fine weather for the majority of the UK.

metoffice.gov.uk

u/Met-Office — 2 days ago

▲ 3 r/UKWeather+1 crossposts

April 2026 weather quiz: Test your knowledge

How closely were you watching the weather in April?

From mean temperatures and sunshine records to named storms and weather features, this quiz puts your April weather knowledge to the test. See how much you remember and find out how well you followed last month’s meteorological story.

metoffice.gov.uk

u/Met-Office — 5 days ago

▲ 3 r/UKWeather+1 crossposts

Many of this week’s questions explore some striking weather facts from the UK and beyond, testing how well you know both the terms used in and the statistics behind the forecast. From understanding what a Spanish Plume is, to recalling England’s coldest night on record.

u/Met-Office — 15 days ago

▲ 4 r/UKWeather+1 crossposts

From extreme rainfall affecting southern Africa to chilly nights and the return of frost risk in the UK, the weather this week highlights just how varied conditions can be at this time of year.

Alongside South African rainfall and the day‑to‑day UK forecast, this week’s Deep Dive will also look back on what April delivered across the UK - a month that brought stark contrasts in rainfall, abundant sunshine for many, and temperatures that behaved very differently by day and by night.

Exceptional rainfall risk in South Africa

While large parts of central Africa are experiencing seasonal rainfall that is not out of the ordinary, attention is focused on South Africa, where exceptionally heavy rain is unfolding over a short period through Wednesday.

The situation involves a deep area of low pressure in the upper atmosphere, known as a cut‑off low, which is positioned close to southern Africa. At high levels, unusually low atmospheric pressure values indicate a very intense system. This feature draws warm, moisture‑laden air southwards, where it wraps back around the low. As this air is forced to rise, it produces prolonged and intense rainfall.

Current forecasts show rainfall totals widely reaching between 75 and 150 mm in around a day, with some locations exceeding this. Over several days, totals build into the hundreds of millimetres. To put this into context, average rainfall for May in some of the affected areas is around 40 mm, highlighting just how unusual and impactful this event is.

Impacts enhanced by terrain and strong winds

The impacts are likely to be heightened by local geography. As moist air is forced upwards over higher terrain, rainfall intensity can increase further. This raises the risk of rapid runoff and flash flooding, with water moving quickly through river catchments.

Forecasts also suggest some rivers could experience flows associated with very long return periods, highlighting the potential severity of the flooding risk. Alongside the rainfall, strong winds are also expected. Gusts may reach levels capable of causing power disruptions and structural damage, compounding the overall hazards.

While conditions are expected to ease later in the week, the combination of heavy rain and strong winds makes this a particularly concerning period for the affected regions.

A quieter but cooler pattern for the UK

Closer to home, the weather across the UK is less dramatic but still noteworthy. The UK sits between areas of high-pressure to the west and low-pressure to the east, resulting in a changeable but not especially unsettled pattern.

There will be a mix of cloud and sunshine, with some outbreaks of rain at times, but nothing on the scale of widespread storms. Rainfall amounts are generally expected to be modest. However, colder air is moving south from the north, bringing a noticeable drop in temperatures.

This colder, clearer air is particularly important when considering night‑time conditions, as it increases the risk of frost in some areas, especially where skies clear and winds fall light.

Showers and a risk of thundery downpours

Although much of the UK will stay dry for long periods, there are areas where showers may develop. Parts of south‑west England, for example, may see convergence zones form, helping to trigger heavier showers. In a few places, these could become locally intense, with hail and thunder possible.

Elsewhere, showers may also develop across eastern parts of the UK, though many places will avoid them altogether. Overall, rainfall is expected to be fairly localised, with long dry spells for many.

Later in the week, low-pressure passing to the north‑west may bring wetter and windier conditions to parts of Scotland, but again these are not expected to be extreme.

READ MORE: May Bank Holiday weather extremes

Turning attention to the weekend

As the weekend approaches, forecast attention turns southwards. There are indications that warmer air could begin to move north from lower latitudes. With this change comes the potential for more widespread and heavier rainfall, possibly accompanied by thunderstorms, particularly later on Saturday and into Sunday.

This shift also signals a recovery in temperatures, following the cooler spell through midweek. While confidence in exact details decreases at this range, it highlights a more unsettled and warmer trend developing.

Frost in May: how unusual is it?

With colder air moving in, a common question arises at this time of year: how unusual is frost in May? The answer depends very much on location.

There are two key types of frost to consider. Air frost occurs when air temperature falls below freezing, while ground frost happens when the temperature at the surface drops below 0°C, even if the air temperature slightly above remains positive.

In May, ground frost is more common than air frost. At this stage of the year, the ground has not yet accumulated as much stored warmth as it does later in summer. This means that similar air temperatures can lead to colder ground conditions than they would in early autumn.

Data shows that on average many northern parts of the UK still experience multiple days of ground frost in a typical May, while southern and coastal areas see fewer due to the moderating influence of the sea.

Last frost dates vary widely

Looking at average dates of the last air frost highlights a clear north‑south pattern. In southern and coastal regions, the average last air frost tends to occur earlier in the spring, often before April ends. Further north, and over higher ground, the average last frost can extend well into May, and in a few places even into June.

This means that frost at this time of year is not especially unusual, particularly in rural and elevated areas. Sheltered valleys are also more prone, as colder air drains downhill and pools near the surface overnight.

Frost and a warming climate

Comparing more recent climate averages with earlier periods shows that the average date of the last spring frost has been shifting earlier in the year. This is consistent with a warming climate.

However, this does not remove the risk of late frosts altogether. In fact, they can become more problematic for gardeners and growers, as plants and blossoms may develop earlier in a warmer spring, leaving them more vulnerable when a late cold snap does occur.

A look back at April: dry, sunny and contrasting

April is likely to be remembered by many as a dry month, particularly across southern and eastern parts of the UK. While western Scotland and some north‑western areas saw wetter‑than‑average conditions, much of the southeast experienced notably low rainfall.

Several counties recorded one of their driest Aprils on record, highlighting the strong regional contrasts. When looking at the UK as a whole, April finished drier than average, despite a wetter start to the month.

Sunshine was another standout feature. UK‑wide, April was markedly sunnier than average, with some southern counties recording their sunniest April on record. This abundance of sunshine played a key role in temperature patterns.

Daytime warmth, cooler nights

April was warmer than average overall, but the warmth was not evenly distributed between day and night. Maximum temperatures were well above average, reflecting frequent sunshine. Minimum temperatures, however, were closer to average, due to clear nights allowing heat to escape.

This combination of sunny days and cool nights is typical of dry spring weather, and it explains why frost and large day‑to‑night temperature ranges can still occur, even during a warmer‑than‑average month.

u/Met-Office — 17 days ago