During the first October decade, 2 coldwaves brings November-like temperatures in large parts of US except for West, where will be persisting extremely hot weather with maximum temperatures of up to 111°F / +44°C /https://mkweather.com/2020/09/29/summer-like-heatwave-up-to-111f-44c-in-southwestern-usa-until-10-october-rains-should-bring-later-ex-hurricane-only-to-the-northern-areas-wildfire-risk-at-an-extreme-levels//.
Only after 10. October should arrive Indian summer to large region in eastern half of the USA and the most populated areas in Canada, thanks to ex-hurricane Marie activity on the West.
First, longer coldwave, arrives between 1. and 5. October 2020 with a widespread impact in central and eastern parts of the USA and eastern Canada.
In Winnipeg, maximum temperature only +7°C, in Ottawa +9°C, in Chicago +12°C, in Rapid City +15°C and in Memphis only +19°C is expected. Series will be associated with a frost and ground frost probability, in northern parts of Ontario and Quebec should appear snowing.
Second, shorter coldwave, should arrive around 8.-9. and hit East, mainly Great Lakes Area and Northeast. Similarly, Arctic blast will be linked with frosts and ground frosts probability and November-like temperatures.
Finally, between 10.-15. October, maybe longer, up to 20. October, long period of Indian summer is expected across eastern-half of the USA and eastern Canada, with really warm and sunny weather, regionally with summer days with maximum temperature above 77°F / 25°C.
At the same time, after 10. October, West hits remnants of hurricane Marie from Pacific /https://mkweather.com/2020/09/29/remnants-of-ex-hurricane-from-18e-eighteen-should-hit-california-until-10-october-area-of-interest-near-mexico-gulf-coast-ex-typhoon-kujira-hit-alaskan-coast//, which brings cooldown and rain to the northern half of the region. Thanks to hurricane activity therefore, in the West will be improved wildfire conditions and in the East people will be experiencing with sunny and warm Indian summer. Not always is effect of hurricanes and their remnants on the weather in the USA destructive.