On July 19 2022, the UK experienced its highest ever temperature. At 40.3℃ (Coningsby, Lincolnshire), the temperature surpassed the previous record of 38.7℃ (Cambridge) – a record that had been set a mere three years previously. My new study shows that this is part of a long-running trend of increasing heat extremes in north-west Europe.

I examined trends in the temperature of the hottest summer day across north-west Europe and compared this to trends in average summer temperatures. My results, published in Geophysical Research Letters, suggest that between 1960 and 2021, north-west Europe has seen its hottest days warm by around 0.6℃ per decade – double the rate at which the region’s average summer days have warmed.

The trend suggests that the region could suffer extremely hot days more often in the future. But this trend isn’t captured in current climate models. While state-of-the-art climate models correctly simulated the trend in average summer temperatures, they failed to capture the enhanced warming of the extremes.

These same climate models are, however, often used to inform impact assessments of climate change. So their inability to simulate the magnitude of trends in extreme temperatures in north-west Europe means that the heat-related impacts of climate change may be underestimated in the short term – and inadequately prepared for as a result.

This is concerning. Infrastructure in north-west Europe is already poorly equipped to deal with extremely hot weather. And extreme heat can have several negative effects on human health and society.

Imported air

The mechanism causing the temperature trends to differ for this region is not yet understood. But the hottest summer days in north-west Europe are often linked to the movement of hot air from over Spain or the Sahara. This was certainly the case in both July last year and July 2019.

Climate change is causing Spain and north Africa to warm faster than north-west Europe. My study found that between 1960 and 2021, the UK warmed by around 0.25℃ per decade compared to more than 0.5℃ per decade for much of Spain. Consequently, plumes of increasingly hot air that are carried north from these regions will bring high temperatures relative to the ambient air temperature of north-west Europe – these temperatures often exceed the threshold to be classified as “extreme”.

Climate models that show Spain and north Africa warming faster than north-west Europe also tend to see a greater rise in heat extremes in north-west Europe relative to mean warming in the future. Although adding further strength to this hypothesis, further work is needed to test the idea more rigorously.

Other possible hypotheses for the enhanced warming of heat extremes include changes to the atmospheric circulation patterns that drive heatwaves. Heatwaves are usually associated with high-pressure “anticyclonic” systems that push warm air northwards. These weather systems are accompanied by clear skies that allow the sun to heat the land.

There is some evidence that the increased occurrence of weather patterns like this could account for the rapid rise in very hot days.

Should we be worried?

The rising intensity of extreme heat in north-west Europe is worrying. Research has found that extreme heat can exacerbate respiratory and cardiovascular diseases and increase the risk of suffering heat stroke. This will put a strain on the health and emergency services.

Much of the infrastructure in the UK – and north-west Europe – is also not designed to deal with extreme heat. In the past, heatwaves have damaged road surfaces and have caused rails to buckle (where they expand and start to curve), leading to severe delays on rail services. On July 19 2022, for example, soaring temperatures meant no trains ran into or out of London King’s Cross rail station.

Homes in the UK also heat up much faster than those in other European countries. According to one study, the temperature inside an average British home will increase by 5℃ in just three hours when the outside temperature is 30℃. That is more than double the rate at which homes across much of western Europe will gain heat.

Yet little is being done to help the same infrastructure cope with even hotter weather in the future. A recent report by the Climate Change Committee, an independent body advising the UK government on its response to climate change, found that the government is not taking sufficient action to adapt to climate change. The report highlighted the need to better heat-proof homes and mitigate wildfire risk as high temperatures become more common.

Over the past 60 years, north-west Europe’s hottest days have become much warmer. These findings indicate that the region is already dealing with the effects of climate change and underline the urgent need to adapt systems and infrastructure to help this area withstand it. From a scientific perspective, we must identify the reasons for the enhanced warming of heat extremes in order to improve current models and find out if this pattern is likely to continue in the future.

Matthew Patterson, Postdoctoral Research Assistant in in Atmospheric Physics, University of Oxford

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Stargazing in national parks

According to a study in Science Advances, more than 99% of people in the U.S. live under light-polluted skies, and nearly 80% of them can’t see the Milky Way. If you look at a map of light pollution, you’ll see the dark pockets often correspond to public, protected lands. The national parks are some of the least light-polluted and therefore best places to observe the night sky in the United States.

The National Park Service (NPS) maintains a Natural Sounds and Night Skies Division in an effort to protect the native soundscape and guard against light pollution in the parks. As far as preserving dark skies, the NPS website says:

The night sky has inspired us for generations. Nighttime views and environments are among the critical park features the NPS protects. Night sky protection enhances qualities of solitude and undeveloped wilderness character that animals depend on for survival, park visitors seek for connections, and many cultural-historical parks require for preservation. In this regard, the NPS recognizes a naturally dark night sky as more than a scenic canvas; it is part of a complex ecosystem that supports both natural and cultural resources.

So, many U.S. national parks have earned the designation of International Dark Sky Park. Of course, these parks must have exceptional and protected dark skies to earn this distinction. Some International Dark Sky Parks include the Grand Canyon, Death Valley, Big Bend, Mammoth Cave and more. You can view the full list here.

In addition, no matter where you live in the world, you can look for a dark-sky site near you at EarthSky’s best places to stargaze.

‘Half the Park is After Dark: Exploring dark-sky parks around the world

To explore the night sky data collected in national parks, visit this website

Stargazing programs in the national parks

Many of the parks hold stargazing events after dark. Park rangers knowledgeable about the night sky point out the highlights and sometimes share views through a telescope. Bryce Canyon National Park even has an annual astronomy festival. Glacier National Park now has the Dusty Star Observatory on the east side in St. Mary, along with star parties at Logan Pass.

Some of the darkest night skies in the U.S. are in the desert of Nevada, and the Great Basin Observatory will capitalize on that. This observatory will be the first research-grade observatory built in a U.S. national park. You can find more national park observatories here.

Before you visit any national park service site, check the NPS website to see what astronomy or observing programs are available to visitors.

Of course, one of the easiest ways to enjoy the night sky in the national parks is to camp out under the stars. Remember to reserve your campground space in advance and hope for clear skies. To see what’s visible in the sky for the night you’re camping, check our Tonight page.

Night-sky photos from the national parks

If you have a great photo of the national parks after dark, share it with us!

Bottom line: Stargazing and the national parks are a great combination. Increasing light pollution in the United States makes national parks some of the last dark refuges.

EarthSky’s Best Places to Stargaze: A crowd-sourced global map of dark sites

On April 27, 2023, Spain recorded its hottest-ever temperature since record-keeping started in 1961. The EU country hit 38.8°C according to the its meteorological service.

According to reports, the spring heatwaves in Spain have slapped the country with temperatures up to 15°C warmer than normal for the month of April. Three years of scant rainfall and high temperatures put the country in a long-term drought only last month.

So, why is this happening?

A combination of multiple factors is responsible for the current situation in Spain. The spring heatwaves in Spain are being caused by a mass of hot air across North Africa pushing heat into Europe, coupled with a high-pressure weather system.

This combination, along with clear skies, makes it easy for sun rays to hit the ground retaining heat and warming up the ground. This will further raise the prospect of early forest fires. In 2022, Spain saw the most land burned of any country in Europe.

The spring heatwaves have also had an impact on the country’s agriculture sector. Spain is the world’s biggest exporter of olive oil, a significant producer of fruits and vegetables for the European market. But the ongoing drought is having an impact on the Spanish olive crops and other staple crops.

This heatwave in Spain is not an isolated event. Temperatures across the world have reached new heights this year with eight countries in central and eastern Europe experiencing their warmest January weather on the day of the new year.

The country of Portugal also saw its highest temperature in 78 years with temperatures in the central town of Mora reaching 36.9°C in the month of April.

Starting in April 2023, a record-breaking heatwave has affected many Asian countries, including India, Bangladesh, China, Thailand and Vietnam. On April 15, 2023, Dhaka, the capital of Bangladesh saw its hottest day in 58 years with the temperature crossing a sizzling 40°C.

In India, things are going a little differently. The India Meteorological Department predicted that the month of May will experience cooler than normal weather, which might also get tricky considering the fact that natural heating of the landmass is vital for monsoon onset and distribution.

With the likely arrival of El Nino, these erratic weather patterns are going to get more unpredictable and will have a tremendous impact on the rest of the summer and monsoon seasons.

The moon to occult Jupiter on May 17

Here’s hoping you have clear skies on the morning of May 17, 2023. For all of us around the globe, the waning crescent moon will be near Jupiter. And, for some, the moon will slide past – and maybe even cover – the gas giant planet.

Astronomers call this event an occultation, when one object in space passes in front of another. In this case, the moon is occulting Jupiter. You could even say that the moon is eclipsing Jupiter.

On that Wednesday morning, the thin waning crescent moon will be only 5% illuminated when it occults Jupiter. Most places will be in daylight during the occultation. Those further west in the areas of visibility may see the occultation occur near or before the sun rises.

A word of caution, be very careful pointing binoculars or telescopes at the sky when the sun is above the horizon. Even a quick glance at the sun through any kind of optical aid can cause permanent blindness.

Where is the occultation visible?

The moon will pass in front of Jupiter as seen from areas that include northern Central America, northern Caribbean, most of North America, Greenland, Iceland, Svalbard, northern British Isles, Scandinavia and northwest Russia.

The map below shows what part of the world gets to view the occultation.

When can I see the occultation?

The moon and Jupiter will rise around 4:30 a.m. local time. The moon will cover Jupiter during daylight in the Eastern time zone, and morning twilight in the Central time zone. Western regions will have the darkest skies. The exact time the moon first passes in front of Jupiter varies by location. Find the start and end times for your location here.

For example, for those in Denver, Colorado, Jupiter disappears behind the moon at 5:32 a.m. MDT, though in twilight. (Sunrise is at 5:41 a.m. for Denver.) Jupiter will reappear at 6:27 a.m. MDT in daylight. For Phoenix, Arizona, Jupiter disappears behind the moon at 4:21 a.m. MST, when the pair are only 1.7 degrees above the horizon. Jupiter will reappear from behind the moon at 5:16 a.m. MST, and sunrise follows at 5:24 a.m. MST.

For those who live outside the viewing area, you’ll see the moon and Jupiter skim right past each other. Some places will even get to see Jupiter play peekaboo along the cratered and mountainous limb of the moon. And some places may see Jupiter about 1 degree away from the moon. It’s all about location!

What will you see when the moon occults Jupiter?

The waning crescent moon will not be very bright in daylight. And it’s only 5% illuminated that morning, shining at -9.27 magnitude. Jupiter is 100% illuminated, shining at -1.9 magnitude, and it’s 33 arcseconds across. So, if your location is still dark, you can see Jupiter with the unaided eye as it gets closer to the moon. However, they’ll certainly be difficult to see in the morning twilight or daylight without optical aid.

Some recent occultations that were easier to see include the December 7-8, 2022, lunar occultation of Mars. And the recent lunar occultation of Venus on March 24, 2023, occurred in an evening sky.

Viewing will be complicated since it’s in daylight

Of course, since most of the occultation takes place in daylight, you’ll need to use binoculars or a telescope to see it. It’s best to set up your equipment in shade to prevent any direct sunlight entering your line of sight. Even a momentary glance at the sun – especially through binoculars or telescopes – can cause permanent eye damage.

Also, people who observe occultations typically try to catch both the disappearance and reappearance of the star or planet as it’s blotted from view. Jupiter will disappear behind the illuminated edge of the moon. And then – after a while – Jupiter will emerge along the darkened edge of the moon.

Start watching the occulation about five minutes before Jupiter disappears from your location. Once it’s gone, there’s not much you can do – unless you have some safe solar viewing equipment – except wait for the planet to reappear from behind the other side of the moon. Again, about five minutes before the scheduled reappearance of Jupiter, start watching in your binoculars or telescope.

When the moon occults Jupiter, it’s a great photo op!

So, what will you see during the occultation of Jupiter? The answer depends on how hard you try, what tools you use, where you are on Earth – as always, on the seeing of your sky – and on your skill at observing events like this.

If you capture a picture of the moon occulting (or passing) Jupiter that you’d love to share, submit it to EarthSky Community Photos.

Bottom line: On the morning of May 17, 2023, the waning crescent moon occults – or covers – the gas giant planet Jupiter. Details here, including how to see it and what to expect.