While abnormally cold weather continues to grip the Eastern United States, a full-fledged dose of summer weather has overtaken much of Europe.

An enormous heat dome, parked over Germany, has covered a large part of the continent in record or near-record warmth.

High temperatures in the 70s and 80s (roughly 20 to 30 Celsius) were widespread Thursday.

The British Met Office tweeted that St. James’s Park in London soared to 84.4 degrees (29.1 Celsius), its warmest temperature in April since 1949, when it hit 84.9 (29.4 Celsius).

Paris also experienced historically warm April conditions. Its temperature surpassed 82 degrees before April 20 for the first time since 1949, MeteoFrance reported.

Etienne Kapikian, a meteorologist with MeteoFrance, tweeted that Paris’s preliminary high of 83.7 degrees (28.7 Celsius) ranked as the fifth-highest April temperature there in 146 years of measurements.

Several locations in France set all-time April highs, MeteoFrance tweeted.

Europe’s warmest conditions relative to normal focused in southeast England, northern France, Belgium, the Netherlands and western Germany, where many locations witnessed temperatures 20 to 30 (11 to 16 Celsius) degrees above normal.

The summery conditions are forecast to persist through the weekend, but the sprawling heat dome should gradually shrink and shift east and southeast.

But even Sunday, London is forecast to reach 74 degrees (23 Celsius), when it is set to host the London Marathon. Such a temperature would make for the warmest race on record (the previous high was 72 degrees, or 22.2 Celsius, in 2007).

“London Marathon runners have been urged to reconsider dressing up in fancy costume,” the Associated Press reported.

The sudden spring heat wave marks an incredible contrast from conditions just six weeks ago, when London and much of Europe were in the deep freeze thanks to Siberian winds dubbed the “Beast from the East.”