The UK is set to experience its warmest day of the year today, with temperatures peaking at 26°C in parts of Southeast England, including Greater London, Essex, and Surrey. This rise in temperature is due to a band of high pressure moving northwards, resulting in warmer conditions across the region. Paul Gundersen, chief forecaster at the Met Office, noted that this warm spell is more typical of late spring or early summer, potentially marking the warmest April since 2020. However, this warmth will be short-lived, as a significant drop in temperatures is expected later this week, with daytime highs potentially falling by 10°C. While central and southeast England will enjoy sunny weather, Northern Ireland and northwest Scotland will experience cloudier and cooler conditions with occasional rain. Additionally, high pollen levels are anticipated, posing challenges for hay fever sufferers, particularly in England and Wales. The Met Office advises those affected to take precautions to minimize exposure to pollen.