Britain, France, Switzerland and Germany have experienced record heat in June, and the weather system could test more records as it rolls across Germany towards Poland.
On Friday, a German record of 41.3C was reached near the city of Saarbruecken close to the French border, Germany's National Meteorological Service said, noting the reading was still preliminary.
In France, dozens of people both young and old have died during the heatwave.
Temperatures above 40C have disrupted rail travel and power generation, sparked alcohol bans, suspended schools and postponed outdoor events.
"The heatwave is going to peak at the weekend, well over 40 degrees in some parts of Germany," said Karsten Brandt, a meteorologist at forecasting site Donnerwetter.de, on Saturday.
The Ironman European Championship long-distance triathlon taking place on Sunday in Frankfurt shortened the cycling and running courses due to the heat, organisers said.
Struggling with the prospect of damage to infrastructure such as buckling roads and swelling train tracks, some major public service providers have sought to reduce traffic.
German national rail operator Deutsche Bahn has given customers the option of cancelling long-distance travel bookings in the next few days without charge due to the heatwave.
The company said its infrastructure was under particular strain because of sun exposure and additional risk to signals, tracks and overhead wires stemming from thunderstorms and wildfires.
Parts of Germany, mainly in the southwest, have already experienced a much hotter June than usual.
The most extreme heat is forecast to begin fading at the weekend, with heavy thunderstorms expected on Sunday.
Across Europe, cultural landmarks have had to close, farming has suffered, and some hospitals have struggled to cope.
The heatwave has pushed temperatures up to 18C above their seasonal average, according to the Reuters Climate Monitor, and is being driven by a phenomenon known as an Omega block.
This weather pattern traps a bulging ball of hot air over regions for extended periods, with cooler air on its fringes.
Demand for electric fans has shot up, and Asian air-conditioning makers have reported a European sales boom.
Most of the housing stock in northern Europe is not built to temper heat but rather to keep it in.
The present heatwave will begin shifting by the end of June, hitting central Europe and the Balkans, the World Meteorological Organisation said.
Scientists said the heatwave would have been virtually impossible without man-made climate change, which has made this week's night-time temperatures 100 times more likely than they would have been even two decades ago.
with DPA
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