UK Experiences Hottest Day of 2025 with 20.6°C on Spring Equinox

The brief warm spell, hotter than Barcelona and Athens, is accompanied by pollution warnings and high birch pollen levels.

Temperatures reached 20.6°C in Northolt, west London, making March 20, 2025, the hottest day of the year so far in the UK.
The warm weather coincides with the spring equinox, marking the start of astronomical spring in the northern hemisphere.
A high air pollution alert has been issued for London due to increased particulate pollutants from mainland Europe.
Warnings have been raised for allergy sufferers as birch pollen levels are high due to the early start of the pollen season.
The warm spell is expected to end soon, with rain and unsettled weather forecast to arrive by Friday and persist through the weekend.