File:Fires in Russia (MODIS 2020-09-25).jpg

English: As autumn 2020 arrives in Siberia, the severe fire season continues unabated with many dozens – if not hundreds – of fires pouring copious smoke across the region.

The Moderate Resolution imaging Spectroradiometer (MODIS) on board NASA’s Terra satellite acquired a true-color image of Eastern Russia on September 23. A broad river of smoke covers much of the Sakha Republic, obscuring the land from view. The smoke stretches roughly 1250 miles from east to west and, at its widest, about 500 miles north to south.

Many red “hot spots” can be seen, particularly at the edges of the smoke. Each marks an area where the thermal bands on the MODIS instrument detected high temperatures. When combined with typical smoke, as in this image, such hot spots are diagnostic for actively burning fire. With the extreme density of the smoke, it is likely that additional hot spots are obscured from view.

Much of Siberia has sweltered under a very hot spring and summer, with temperatures peaking in the city of Yakutsk at 93˚F (33.9˚C) on July 13 and again on July 19. Average highs on those dates are less than 80 ˚F (26.7˚C). Typically, temperatures fall precipitously in September with average high temperatures on September 23 reported as 38.7 ˚F (3.7˚C). On that date this year, the temperature was 52˚F (11.1˚C) – cool, but still 13.3˚F (7.4˚C) above average.