The latest weather buzz

Weather updates from site founder Brian Gaze that keep you in the know.

How soon could the UK hit 30C this year

When will 30°C be officially reached for the first time this year in the UK? In the 1970s and 80s it wasn't even a given that the milestone would be reached, 1972, 1974, 1978, 1980 and 1981 all fell short. However, the last time this happened was in 1993, when the maximum temperature recorded was 29.7°C at East Bergholt, Suffolk. Are there any reasons to think it might be recorded particularly early this year or not at all?

Dry ground, high pressure and SSTs

The lack of rain recently means that the ground in much of the UK is now very dry. This will help temperatures to rise more quickly than would be the case if the land were saturated or very wet, as it was last year. Of course it's just one ingredient, but others are in place. Sea surface temperatures (SSTs) around the UK are mostly above the long-term average. In addition, there has been a tendency for high pressure to dominate the weather recently, which in late spring and summer is likely to increase the chance of high temperatures.

Finally, in recent years we seem to have experienced a pattern of several wet seasons being followed by several dry ones. It’s a tenuous correlation given the short time period, but perhaps one worth bearing in mind

30°C spotted in the computer model output

Every day hundreds of computer model runs produce various types of weather forecasts. I won’t go into the details here, but output from the Canadian Global Model today has shown 30°C being reached on Wednesday 30th April, which is nine days away.

The chart below shows the forecast temperatures from the Canadian model, while the one above displays pressure patterns and temperatures at around 1,500 metres above sea level (ASL). These are often used in weather forecasting because they provide a good indication of the air mass and are not affected by diurnal (day-to-night) variations.

When it comes to the UK’s weather nine days is a very long time. In fact, Harold Wilson’s superlative, 'A week is a long time in politics,' barely scratches the surface! Nonetheless, the fact that 30°C is being shown at all suggests that if the pressure patterns develop in a certain way the other variables are in place to enable it to happen very early this year. So whilst subsequent updates of the same (and other) computer model are likely to show a very different picture, it's not at all out of the question that 30°C could be reached in May this year.

It's worth taking a look at some UK temperature statistics from recent years. 

Date 30°C was reached in recent years

Here are the dates for the last 5 years when 30°C was reached for the first time:

2020: 32.6°C, 24th June, Heathrow

2021: 31.6°C, 17th July, Heathrow

2022: 32.7°C, 17th June, Santon Downham, Norfolk

2023: 30.5°C, 10th June, Heathrow

2024: 30.0°C, 25th June, Chertsey, Surrey

Maximum UK temperatures since 2015

These are the highest temperatures officially recorded in the UK for every year since 2015.

2024: 34.8°C, 12th August, Cambridge

2023: 33.2°C, 9th September, Kew Gardens

2022: 40.3°C, 19th July, Coningsby, Lincolnshire

2021: 32.2°C, 21st July, Heathrow, Middlesex

2020: 37.8°C, 31st July, Heathrow, Middlesex

2019: 38.7°C, 25th July, Cambridge Botanical Gardens

2018: 35.3°C, 26th July, Faversham, Kent

2017: 34.5°C, 21st June, Heathrow, Middlesex

2016: 34.4°C, 13th September, Gravesend, Kent (Note: This was in the meteorological autumn)

2015: 36.7°C, 1st July, Heathrow, Middlesex

What do you think?

If you'd like to throw your hat into the ring and make a prediction you can do so in the forum thread When will 30°C be reached for the first time in the UK in 2025? As an added incentive, you could win premium access to TWO until the end of 2025. It gives you ad-free access as well as premium features such as 3D Earth Weather Forecast. You'll also get access to the brand new MATLAB UKV chart plotter which will be launching soon. If you're not already a member of the forum you can register here.