On Thursday, March 20, 2025, London is poised to experience what may be the warmest day of the year, with temperatures projected to soar to as high as 21°C, coinciding with the spring equinox—an astronomical event heralding the start of spring.
According to Met Office meteorologist Simon Partridge, “The highest temperatures are expected in an area from London, the home counties to southern Midlands. Here we are likely to see 19°C or 20°C widely with one or two spots likely to reach 21°C.” This marks a significant jump from an earlier record of 19.7°C set in Crosby, Merseyside, on March 9, 2025.
Compounding the excitement of the weather, London will reportedly be hotter than renowned holiday spots like Madrid, which is forecasted to have a high of just 19°C, and even the Algarve in Portugal, expected to reach only 15°C. Residents can anticipate an exceptionally warm day, perfect for outdoor activities.
In the midst of this mini heatwave, however, a high air pollution alert has been issued for the capital. Following a report from Imperial College London, residents have been warned of elevated air pollution levels moving in from mainland Europe, necessitating caution among citizens.
Mayor of London Sadiq Khan has urged residents to avoid unnecessary car journeys and switch off engines while stationary, in a bid to mitigate the air pollution. “We’re predicting high pollution levels in London due to pollution blown across the channel from mainland Europe. I urge Londoners to avoid unnecessary car journeys, switch engines off while stationary, and refrain from burning wood or garden waste,” Khan said via X.
The scene in London is lively, with residents cherishing the warm weather after a long winter. Londoners have taken to sharing photos of blue skies and springtime flowers on social media, with many expressing joy as they embrace the first signs of spring—a marked contrast to the persistent winter chill.
Celebrations unfolded at Stonehenge as people gathered to commemorate the spring equinox with music and dancing, showcasing traditions rooted in this seasonal change.
As pollen levels rise alongside temperatures, those who suffer from asthma or allergies are advised to be cautious. Reports indicate that this year could see a significantly worse hay fever season due to higher pollen counts, affecting approximately 20 percent of the population. As such, individuals with respiratory issues are particularly urged to take precautions.
Educational initiatives from organizations like the National Trust also encourage people to step away from their desks to enjoy nature, where 94% of surveyed UK adults reported that blossom scenes uplift their spirits. With cherry blossoms blooming, parks across London become picturesque havens for those seeking a retreat from routine.
Despite the warm forecast, cooler temperatures are expected to return following this warm spell. The Met Office indicates that after reaching a high of potentially 21°C on Thursday, temperatures are expected to drop to around 14°C by Sunday, March 23, 2025. Rain is also anticipated to make an entrance, reminding residents that the UK's typically unpredictable weather remains a part of life.
As Londoners revel in the unique opportunity to enjoy a warm spring day while being mindful of air quality and allergy conditions, the celebration of the spring equinox blends seamlessly with the joy of the forthcoming season. This contrast serves as a reminder of nature's duality—beauty intertwined with challenges, especially as the climate continues to evolve in these dynamic times.
