Heat dome to bring fierce temperatures and humidity to much of US
Summer will make a dramatic entrance in the US this week with a heat dome that will bring stifling temperatures and uncomfortable humidity to millions.
The heat will be particularly worrisome this weekend across wide stretches of Nebraska, Illinois, Wisconsin and Iowa, where forecasters are warning of extreme temperature impacts.
This will be the first stretch of true summertime weather for many from the midwest to the east coast, said Tom Kines, a meteorologist at the private weather company AccuWeather.
'A lot of those folks have been saying, where's summer? Well, buckle up, because it's coming,' said Kines. The humid conditions will make places that exceed 90F (30C) feel as much as 20F hotter, said Kines.
A heat dome occurs when a large area of high pressure in the upper atmosphere acts as a reservoir that traps heat and humidity, said Ricky Castro, a National Weather Service meteorologist in Illinois.
According to the NWS Weather Prediction Center, daytime temperatures will be in the 90s (30s Celsius) and overnight temperatures will only drop to the mid-70s (mid-20s Celsius) from the Great Lakes to the east coast during the heat wave that's expected to last into next week.
Moisture blown north from the Gulf of Mexico is fueling the muggy weather, said Jacob Asherman, a Weather Prediction Center meteorologist. This influx of Gulf moisture is fairly typical during late spring and summer, he said.
The heat will be widespread into next week. On Friday, Denver could reach 100F (38C), according to the weather service. Chicago temperatures could reach 96F (36C) on Sunday. On Tuesday, Washington DC could see a high of 99F (37C) and New York City could reach 96F (36C).
Several states in the midwest could see dangerous temperature impacts over the weekend, according to a weather service measure that rates the risk from zero to four. Parts of Nebraska and Kansas will be in the highest category on the scale on Saturday, meaning that anyone without effective cooling or sufficient hydration could face health risks. On Sunday, Iowa, Wisconsin, Missouri and Illinois also see a category 4 rating.
Humidity is the amount of water vapor in the air, and the heat index is what the temperature feels like when the humidity outside is factored in, according to the weather service.
When humans sweat, it cools the body down because it absorbs and removes heat as it evaporates off the skin. The air is saturated with water on humid days, which makes it harder for sweat to evaporate. Hot and humid days can be dangerous when the body is unable to cool itself off and can exacerbate pre-existing health conditions and even lead to heat stroke.
Minimizing direct sun exposure, wearing loose and light-colored clothing, staying hydrated and spending time in air-conditioned spaces are ways to cool down during extreme heat, according to the NWS.
Some parts of the US, such as Phoenix, Arizona, are famously hot without the mugginess. Phoenix and nearby desert regions experience this so-called 'dry heat' due to being located far away from large water bodies, mountains that block moist air masses and weather patterns that bring scarce precipitation.
Sweat evaporates faster in dry climates compared to humid ones. This can be dangerous because it is easy to underestimate how dehydrated you are, according to Johns Hopkins University and Johns Hopkins Health System.
In places such as Iowa, crops can affect the humidity in summer months. Plants feel the effects of hot weather and some people in the midwest are familiar with 'corn sweat', which is when crops move water to their leaves and other surfaces so it can evaporate, according to the Ohio State University.
Iowa, farmer Ryan Marquardt said corn sweat is 'not as bad as a sauna, but it definitely would have a sauna effect. It's humid in there [the cornfield], so you're gonna sweat.'
Cornfield contributions to the overall humidity are much lower compared to the humidity winds carry from the Gulf of Mexico, according to OSU.
Hashtags
Try Our AI Features
Explore what Daily8 AI can do for you:
Comments
No comments yet...
Related Articles
Reuters
6 hours ago
- Reuters
What late-June sizzle could mean for US corn yields: Braun
NAPERVILLE, Illinois, June 18 (Reuters) - Although the U.S. Corn Belt is in for a scorching weekend, June weather has been mostly supportive of crop development, with corn health ratings improving for three consecutive weeks. But how much bearing might that have on final corn yields or weather outcomes for the pivotal month of July? As early as last year, meteorologists warned that the U.S. Corn Belt could be due for drought in 2025, though that has yet to unfold. A mid- or late-summer drought could still be in the cards, of course, and the yield impacts would vary depending on timing. Recently, new-crop CBOT corn futures appeared to be carrying minimal weather premium as prices sank to six-month lows this week. December corn has since bounced with this weekend's hot forecast in focus, though prices remain well off the year's peak. Recent weather models suggest that both temperatures and precipitation for June will be above average across the Midwestern United States. While warm Junes are more likely to feature dry conditions, this warm-wet combination is similar to last year. Corn yield outcomes have varied widely in relation to observed June weather. But July temperatures are where things start to separate. In the past quarter-century, the worst corn yield outcomes all coincided with warmer-than-normal Midwestern Julys. The truly good years featured cool Julys, but slightly warm temperatures were also passable a couple of times (2016, 2017). Big corn yields have resulted from abnormally dry Julys (2014), though this works only if July is cool and June and/or August rainfall is ample. The strongest corn yields all resulted in years where July-August Midwestern rainfall was near or above normal. Near-average yields have coincided with dry July-Augusts, but only when July temperatures were cool. Obviously, a hot July plus a dry July-August is the very worst combination for yields, which was seen in 2011 and 2012. Interestingly, 2011 is the last time that corn conditions improved over the same three weeks in June as the 2025 ones. But the fact that June 2025 will likely feature above-average rainfall doesn't tell us much about what's coming next. July and August have been both wet and dry following wet Junes, though warm Julys are more likely to follow warm Junes. Current extended forecasts suggest the next four weeks could be warmer than average across the central Corn Belt, featuring pockets of both wet and dry weather. Uncertainty is always high when it comes to long-range forecasts, but the current outlook should warrant some caution. August matters for U.S. soybean yields like July matters for corn. Last year, the market was harshly reminded of the need for August rains to support large soybean yields. August 2024 rainfall across the Midwest amounted to just 87% of normal, the driest August since 2013. But 2024 U.S. soybean yield forecasts were still easily at record levels as late as October. The government's yield estimate plunged 4.5% between October and January, the largest decline for that period since 1993, emphasizing the significance of the August rainfall deficit. That occurred despite above-average June and July rains, meaning the range of possibilities for U.S. soybean yields is even wider than those for corn given that August is still several weeks away. Karen Braun is a market analyst for Reuters. Views expressed above are her own. Enjoying this column? Check out Reuters Open Interest (ROI), opens new tab, your essential new source for global financial commentary. ROI delivers thought-provoking, data-driven analysis of everything from swap rates to soybeans. Markets are moving faster than ever. ROI, opens new tab can help you keep up. Follow ROI on LinkedIn, opens new tab and X., opens new tab
Telegraph
6 hours ago
- Telegraph
Ascot racegoer in hospital with heatstroke as hundreds treated by medics
Hundreds of racegoers were treated at Royal Ascot's medical centre over the opening two days as the heatwave surged to 28C. One spectator to fall ill with suspected heatstroke was sent to hospital on Tuesday, with crowds warned temperatures will hit 31C by Saturday. By early evening at the racecourse on Wednesday, a total of 121 had reported themselves to medics on that day alone. Yet again lengthy queues had been forming at the water dispensers, in some cases longer than the bars, as crowds in top hats and tails sweltered. An Ascot spokesman told Telegraph Sport that extra gazebos and parasols had been erected around the grounds to help provide extra shade. 'As of 5.30pm today, there had been 121 heat-related calls to the medical centre from a total number of around 200 in an overall crowd of 41,571,' a spokesman added. 'That overall number is less calls than yesterday. One person has been taken to hospital due to heat-related illness. We have once again been providing free water at hydration stations across all enclosures and free bottled water is being handed out on exit.' Official temperatures reached a maximum of 27.9C on the course, but for many it felt much hotter in the areas where crowds have been denser. Crowds are up this year and there has been little sign of trouble, despite the stifling heat. The first race of the meeting's second day was overshadowed, however, by the death of Harry's Girl. Harry's Girl, trained by Richard Hannon, was pulled up with a serious leg injury by jockey Sean Levey during the Queen Mary Stakes. The filly broke down midway through the five-furlong sprint for two-year-old horses. 'Our thoughts go out to all connections at this time,' a spokesman said as festival recorded its fourth death in 10 years. The race was won by 9-4 favourite True Love, under Ryan Moore for trainer Aidan O'Brien, from 100-1 shot Flowerhead. A mobile bowser, misting fans and 3,000 litres of iced water are keeping the horses cool. Gosdens strike again as Ombudsman finds route through traffic Royal Ascot may only be two days old but a pretty clear pattern is emerging; John and Thady Gosden take the day's big race and one other for good measure. Everything the Gosdens have touched this week seems to have turned to gold – a good sign for Trawlerman's chances in today's Gold Cup – but even they could not get the King and Queen on the scoresheet after Rainbows Edge became their second beaten favourite of the week, only finishing midfield in the Kensington Palace Stakes. Without wishing to risk the Tower, the Queen might now concur with the old racing superstition that wearing green is considered unlucky at the races. But with Tuesday's St James's Palace already in the bank courtesy of Field Of Gold, Wednesday was the turn of the Godolphin-owned 7-1 shot Ombudsman to star for Gosden and son after running out a two-length winner of the Prince of Wales's Stakes. Any victory, let alone a clear-cut one, looked an outside bet, however, as the four-year-old was repeatedly denied a run inside the penultimate furlong. Ombudsman wins the Prince Of Wales's Stakes under @WilliamBuickX for Godolphin 🔵🏆 #RoyalAscot — ITV Racing (@itvracing) June 18, 2025 Sometimes being held up in traffic and having to take a 'breather' while everyone else is flat to the boards is no bad thing and that is, essentially, what Ombudsman had to do as he went sideways from inside rail to outside, knocking on each door, only to be turned away as he went. Did the field go too quick in the Prince Of Wales's Stakes? 🤔 @Ruby_Walsh gives us his opinion 💬 — ITV Racing (@itvracing) June 18, 2025 However, the Ballydoyle pacemaker Continuous had set a pretty ferocious gallop for Los Angeles, which set it up for someone coming off the pace. When William Buick finally found daylight, Ombudsman showed his rivals a clean pair of hooves coming home two lengths ahead of Anmaat and See The Fire. 'The plan was to just relax off the pace, which was strong and set up for Los Angeles, who is a real dour, long-striding staying horse,' explained Gosden, who notched up his 70th Royal Ascot winner. 'It was just the question of when you get in the straight, would you get the luck? William wasn't in a position where he could swing around the field; it was more a case of waiting for the gap. And he was very patient, but I knew when he got a gap at the furlong pole, that this horse has an extraordinary turn of foot. So he was patient and he was rewarded. 'I think it is all down to the owner Sheikh Mohammed, because I said, 'look, he's an immature horse, give me a chance with him', and he said, 'take as long as you like'. Sheikh Mohammed is without doubt the easiest owner I've ever trained for. Now Ombudsman has fully grown and developed – a proper four-year-old – the owner is getting rewarded. When you are a trainer, it's very nice to train for people who aren't putting the pressure on.' The leading owner at this meeting with three winners so far is Wathnan, the big-spending Qatari outfit. Clearly being Wathnan-owned and Gosden-trained, Crimson Advocate was meant to be in the Duke of Cambridge. She won the Queen Mary two years ago for US trainer George Weaver before she was bought by Wathnan and, eventually, transferred to Newmarket. Ridden cold by James McDonald, she flew at the finish to win by a length and three quarters. Crimson Advocate wins the Duke Of Cambridge Stakes under @mcacajamez 🏆 Another big win for Wathnan Racing 💪 #RoyalAscot — ITV Racing (@itvracing) June 18, 2025 Having landed the Coventry with Gstaad on Tuesday, Aidan O'Brien took the Queen Mary with True Love, probably the biggest filly in the race, who beat the Amo-owned 100-1 shot Flowerhead a length and a quarter. She had been beaten on both her previous starts, once by Gstaad and once by the unbeaten Lady Iman. Another juvenile winner for Aidan O'Brien and Ryan Moore 👏 True Love wins The Queen Mary Stakes ❤️ #RoyalAscot — ITV Racing (@itvracing) June 18, 2025 'She's lovely,' O'Brien said. 'She looks like a four-year-old. After her first run Ryan said they won't beat her again and after her second, Wayne [Lordan] said the same and you've seen what they did. Ryan said she might be better over six but No Nay Never is a big influence for speed, so you never know.' Paddy Twomey, who describes himself as a 'small' trainer (relative to what I am not quite sure) but has only had five horses out of the first three from 61 runners this season at home, and has a reputation for being the shrewdest trainer in Ireland. He saddled his first Royal Ascot winner when Carmers, named after the owner-breeder Fiona Carmichael's late husband, won the Queen's Vase and set himself up for a possible crack at the St Leger. It was the horse's third start and third win and he set a course record in the process. The well-backed Carmers wins the Queen's Vase under Billy Lee 💜💚 @ptwomeyracing | #RoyalAscot — ITV Racing (@itvracing) June 18, 2025 Eve Johnson-Houghton, an outspoken critic of some of the changes about to be implemented to the conditions of the Windsor Castle, including making it a six-furlong contest, prevented a Ballydoyle whitewash of the juvenile races when Havana Hurricane and Charlie Bishop won the Windsor Castle. She won the same race in 2021 with Chipotle.
The Guardian
6 hours ago
- The Guardian
Heat dome to bring fierce temperatures and humidity to much of US
Summer will make a dramatic entrance in the US this week with a heat dome that will bring stifling temperatures and uncomfortable humidity to millions. The heat will be particularly worrisome this weekend across wide stretches of Nebraska, Illinois, Wisconsin and Iowa, where forecasters are warning of extreme temperature impacts. This will be the first stretch of true summertime weather for many from the midwest to the east coast, said Tom Kines, a meteorologist at the private weather company AccuWeather. 'A lot of those folks have been saying, where's summer? Well, buckle up, because it's coming,' said Kines. The humid conditions will make places that exceed 90F (30C) feel as much as 20F hotter, said Kines. A heat dome occurs when a large area of high pressure in the upper atmosphere acts as a reservoir that traps heat and humidity, said Ricky Castro, a National Weather Service meteorologist in Illinois. According to the NWS Weather Prediction Center, daytime temperatures will be in the 90s (30s Celsius) and overnight temperatures will only drop to the mid-70s (mid-20s Celsius) from the Great Lakes to the east coast during the heat wave that's expected to last into next week. Moisture blown north from the Gulf of Mexico is fueling the muggy weather, said Jacob Asherman, a Weather Prediction Center meteorologist. This influx of Gulf moisture is fairly typical during late spring and summer, he said. The heat will be widespread into next week. On Friday, Denver could reach 100F (38C), according to the weather service. Chicago temperatures could reach 96F (36C) on Sunday. On Tuesday, Washington DC could see a high of 99F (37C) and New York City could reach 96F (36C). Several states in the midwest could see dangerous temperature impacts over the weekend, according to a weather service measure that rates the risk from zero to four. Parts of Nebraska and Kansas will be in the highest category on the scale on Saturday, meaning that anyone without effective cooling or sufficient hydration could face health risks. On Sunday, Iowa, Wisconsin, Missouri and Illinois also see a category 4 rating. Humidity is the amount of water vapor in the air, and the heat index is what the temperature feels like when the humidity outside is factored in, according to the weather service. When humans sweat, it cools the body down because it absorbs and removes heat as it evaporates off the skin. The air is saturated with water on humid days, which makes it harder for sweat to evaporate. Hot and humid days can be dangerous when the body is unable to cool itself off and can exacerbate pre-existing health conditions and even lead to heat stroke. Minimizing direct sun exposure, wearing loose and light-colored clothing, staying hydrated and spending time in air-conditioned spaces are ways to cool down during extreme heat, according to the NWS. Some parts of the US, such as Phoenix, Arizona, are famously hot without the mugginess. Phoenix and nearby desert regions experience this so-called 'dry heat' due to being located far away from large water bodies, mountains that block moist air masses and weather patterns that bring scarce precipitation. Sweat evaporates faster in dry climates compared to humid ones. This can be dangerous because it is easy to underestimate how dehydrated you are, according to Johns Hopkins University and Johns Hopkins Health System. In places such as Iowa, crops can affect the humidity in summer months. Plants feel the effects of hot weather and some people in the midwest are familiar with 'corn sweat', which is when crops move water to their leaves and other surfaces so it can evaporate, according to the Ohio State University. Iowa, farmer Ryan Marquardt said corn sweat is 'not as bad as a sauna, but it definitely would have a sauna effect. It's humid in there [the cornfield], so you're gonna sweat.' Cornfield contributions to the overall humidity are much lower compared to the humidity winds carry from the Gulf of Mexico, according to OSU.
