MAY 2025

UNITED STATES

Severe thunderstorms have battered parts of the US this week as the storm season reaches its climatological peak. The outbreak began last Friday, with Kentucky and Missouri worst affected. Powerful tornadoes associated with supercell thunderstorms whipped across swaths of the Midwest, resulting in 25 deaths. One tornado tore through St Louis, killing seven people. Further rounds of severe thunderstorms struck farther west in Oklahoma and Kansas over the subsequent days, moving eastwards over the course of the week. One tornado narrowly missed the city of Greensburg, Kansas, which had previously been devastated by an EF5 tornado – the highest rating – in 2007. Strong tornadoes and hailstones more than 10cm (4in) in diameter were reported early this week. Further severe thunderstorms are likely over the coming days across the region but are unlikely to be as severe or widespread.

Kentucky’s governor, Andy Beshear, confirmed in a social media post that deaths in Kentucky had risen to 19 after the addition of a woman from Russell County. “Please join Britainy and me in praying for the families who are hurting right now,” the post read. The storms were part of a weather system on Friday that killed seven people in Missouri and two in northern Virginia and spawned more than two dozen tornadoes in Missouri, Kentucky, Illinois, and Indiana. It left several hundred thousand customers without power in the Great Lakes region and brought a punishing heatwave to Texas. Meteorologists on Sunday predicted a fresh “multi-day” mix of dangerous weather conditions across the country’s midsection with heavy rains, thunderstorms, and potential tornadoes, according to the National Weather Service (NWS).

ASIA

Residents of Delhi and the surrounding areas woke up last week to severe thunderstorms with intense rainfall, large hailstones, and squally winds. The storms arrived in the early hours of the night, lasting six hours before easing by about 8.30 am on Friday morning. At Safdarjung, the primary weather station in Delhi, 77mm of rain was recorded, the majority of which, 60mm, fell within the first three hours. The event itself was the second-highest 24-hour rainfall total in Delhi during May since 1901. The deluge of rain led to flash flooding, felled trees, widespread disruption, and claimed seven lives. Further sharp showers are forecast across India this week, alongside thunderstorms across western and central parts where relatively cooler air will become situated aloft through the course of Monday and promote convection. Some forecast models show the potential for thunderstorms to produce very heavy rainfall, particularly in Gujarat and southwest Rajasthan, until Thursday. However, due to the nature of thunderstorm formation, the exact intensity can be difficult to forecast days ahead, and often still proves too tricky to predict on the day. So the conditions in Delhi on Friday morning may not have been a one-off.

AUSTRALIA

The body of a 60-year-old woman has been found in flood waters on the NSW mid-north coast, bringing the death toll to three, with authorities still holding grave fears for another person who is still missing. The region is battling flooding which has “smashed through” communities on the mid-north coast and parts of the Hunter. The NSW premier, Chris Minns, told reporters on Thursday “We’re seeing levels of rise in local tributaries, creeks [and] rivers that we haven’t seen since 1920”. “Many people would have never seen this level of inundation or flooding in their communities,” Minns said. On Thursday evening, NSW police northern regions commander David Waddell announced the third reported death in the floods, which have been brought on by three consecutive days of rain.

Persistent and heavy rain has caused significant flooding on the mid-north coast of New South Wales, with emergency services issuing warnings for people to evacuate from some low-lying areas on Tuesday afternoon. The State Emergency Service (SES) said further intense falls of more than 140mm were likely over the 24 hours to Wednesday afternoon, with some isolated areas expecting in excess of 200mm.  Much of NSW’s mid-north coast and Hunter region had so far copped the barrage, with 24 flood rescues in the past 24 hours. As of Tuesday morning, the State Emergency Service had received 2,000 calls in the same period, responded to 1,400 incidents, and evacuated 60 people.

NEW ZEALAND

Strong winds and flooding spread across New Zealand last week, with a state of emergency declared in Christchurch, after the country was battered by a destructive area of low pressure. A red warning, the highest warning level, was issued by the MetService (the national meteorological service).  The area of low pressure quickly deepened in the Tasman Sea off the west coast of New Zealand and traveled eastwards, with the center of low pressure moving across the northern island and creating very strong winds, particularly through the Cook Strait, the body of water that separates the two islands. The wind direction was south-easterly to southerly, which caused the winds to strengthen as they were funneled between the islands. New Zealand’s capital, Wellington, recorded some of the strongest winds, with gusts exceeding 90mph. Flooding was also an issue, especially for the southern island as the winds brought in moist air from the sea which rapidly rose over the Southern Alps producing heavy rain. More than 100mm of rain fell in less than 12 hours across some eastern areas and the local government called a state of emergency in Christchurch, the largest city in the southern island, as rivers burst their banks and roads closed. Snow warnings were issued across mountainous areas, with some parts experiencing more than 50cm of snowfall in 24 hours. A large swell was produced by the area of low pressure, with waves of almost 6 meters through the Cook Strait.

Meanwhile, large areas of Europe are experiencing above-average temperatures, particularly in central and north-west regions. Temperatures in Vienna in Austria are expected to soar above 30C through the weekend, more than 10C above the average. Some cities in Germany and France are also expected to experience temperatures of about 30C.  The high temperatures are a result of a low-pressure system over Portugal that will continue to drive a warm southerly flow across Europe. However, the high temperatures are not forecast to last, as a cooler northerly flow develops across Europe into next week. This will cause temperatures to drop to about 10C below average, with places that were reaching high 20C this week struggling to get maximum temperatures much above low teens.

CLIMATE

The sea off the coast of the UK and Ireland is experiencing an unprecedented marine heatwave with temperatures increasing by as much as 4C above average for the spring in some areas. Marine biologists say the intensity and unprecedented nature of the rise in water temperatures off the coasts of Devon, Cornwall, and the west coast of Ireland are very concerning. As human-induced climate breakdown continues to raise global temperatures, the frequency of marine heatwaves is increasing.  “This is unprecedented because it is happening so early in the year,” said Dr Manuela Truebano, from the School of Biological and Marine Sciences at the University of Plymouth. “To see these temperature rises around UK waters at this time of year is quite sobering. Each time it happens we use the word ‘unprecedented’, and I am very concerned at the increase in prevalence and intensity of these marine heatwave events.