Neither Siberia, neither Canada or Himalayas, but Greenland.
The coldest place of the Earth in January 2021 took place in Summit (3210 MASL) on 29. January 2021, with minimum temperature only -61,3°C (-78.3°F).
In Antarctica is summer now, but continent experiences with the coldest conditions since 1978 /https://mkweather.com/2021/01/24/antarctica-set-to-coldest-january-since-1978-southern-hemisphere-hasnt-been-so-cold-almost-10-years//. In Dome Fuji was measured in January 2021 freezing -44,1°C on 19.1..
Heatwaves in Australia aren´t this year o strong (any overreaching of +50°C), but in Roebourne it was measured +47,1°C on 14. January.
Mexico was the hottest country in Northern Hemisphere, with +42,0°C in Andres Figureoa on 1.-2. January 2021.
It is possible, that extreme low temperatures in Greenland should during February 2021 repeat, mass of extremely cold air will flood Canada and the USA, too, soon /https://mkweather.com/2021/02/02/deadly-cold-at-the-weekend-windchill-70f-57c-in-the-usa-and-90f-68c-in-central-canada//.
All-time record from Greenland , -69,6°C from 22. December 1991 and it is cca 2°C lower temperature such recognized Russian temperature records from Oymyakon and Verkhoyansk /https://public.wmo.int/en/media/press-release/wmo-verifies-696%C2%B0c-greenland-temperature-northern-hemisphere-record/.