As the world prepares for spring, the vernal equinox arrives on March 20, 2025, bringing with it the promise of warmer weather and longer days for the Northern Hemisphere. This year's equinox is remarkable not only for marking the official start of spring but also for potentially being the hottest day of the year so far, with the Met Office predicting temperatures in London could reach a high of 21 degrees Celsius.
Weather forecasts are predicting that various regions in the UK might even see warmer temperatures than Barcelona and Athens, where the anticipated highs linger in the mid-teens. If temperatures surpass 20 degrees Celsius in London, it will exceed the current record of 19.7 degrees Celsius, which was previously recorded in Crosby, Merseyside, earlier this month. Meteorologist Marco Petagna stated, "Temperatures already just started to pick up in places, but the trend to warmer temperatures is going to continue for the next few days now. So Wednesday, lots of sunshine around parts of southern England and Wales.”
Indeed, on March 19, London is expected to reach highs of around 17 degrees, a significant increase compared to the weather earlier in the week. The metrological attention, however, is primarily focused on March 20, with 21 degrees forecasted, alongside dry and sunny conditions ideal for outdoor activities.
The arrival of the spring equinox is not just about temperature hiking; it plays a crucial role in our understanding of Earth’s position relative to the sun. The equinox occurs at a precise moment when the Earth’s axis is neither tilted toward nor away from the sun, allowing both hemispheres to bask in equal sunlight. This equilibrium leads to nearly equal lengths of day and night, a phenomenon captured in the etymology of the term “equinox,” derived from Latin words meaning “equal and night.”
As the sun travels directly over the equator at noon on this day, the equinox represents a time when the North and South Poles enjoy sunlight simultaneously. Events celebrating this astronomical occurrence have taken place for centuries around the globe. For instance, Nowruz—the Iranian New Year—coincides with the spring equinox, marking a time of renewal and cultural significance.
Additionally, at the ancient Mayan site of Chichen Itza in Mexico, thousands gather to witness the sunlight casting a shadow resembling a serpent – an ecstatic event occurring during the equinox. Such traditions highlight the significance of this celestial event across various cultures.
As the warmth of spring starts to unfold, public anticipation grows. Notably, while March 20 may herald a glimpse of summer heat, the pleasant weather a day prior will fade as forecasts indicate a downward temperature trend. As Mr. Petagna warns, “Temperatures are coming down from Friday onwards, and also some rain pushing in from the South and West.”
For the weekend of March 22-23, temperatures are expected to decline to about 15 or 16 degrees Celsius on Saturday, dipping to a chillier 13 degrees by Sunday. Thus, while residents of London and elsewhere in the UK anticipate the warmest day of the year, they should also prepare for the typical unpredictability of British spring weather.
Looking ahead, the equinox serves as a remarkable reminder of nature's cycles. Its celestial significance connects humanity to the rhythms of the earth. While science illuminates the physics at play, cultural practices allow individuals to celebrate personal and collective renewal as the equinox breathes life into the season of spring.
In wrapping up this seasonal transition, it is important to remember that these astronomical events, while scientifically fascinating, also bridge human experience with nature's perpetual dance. People across generations and cultures will continue to rejoice in the equinox, even as spring's warmth beckons us outdoors once more.
