Wildfires have always existed and, in many instances, we have been able to deal with them. In fact, many species and ecosystems require a specific fire regime in order to survive. Nonetheless, wildfire disasters have frequently occurred due to where we live, how we live, and how we (mis)manage forests and human-caused fire ignitions. I discuss these issues for Australia and Colorado in https://global.oup.com/academic/product/disaster-by-choice-9780198841340 but the lessons apply for many other locations.
The scientific answer would be the geological epoch of the anthropocene, where the human action has pushed the environmental capabilities of the Earth to a hazard boundaries
For wildfires and climate change, I just published https://www.psychologytoday.com/gb/blog/disaster-choice/202009/does-climate-change-cause-wildfire-disasters
There is no question that climate change is major but not only driver in the increased frequency and intensity in places like California and Australia, but the smoke and air pollution from them do not know international borders.
The whole area or state may have serious complications in the nearest future. But, what could be the reason for such multiple starting points, what it indicates ??
I am no expert on this, but I think poor forest management plays a role as there is too much build up of very flammable material on the ground. There have been problems with the main utility in Northern California, the Pacific Gas and Electric Company whose downed lines in storms have sparked fires. And since I think more than 50% of land lost is Federally managed land, I do not think the Trump has adequately helped as we know he is not fond of California and other mostly Democratic states; he plays favorites which is totally unacceptable in crises like this.
"Mother Nature" is saying "#MeToo". She's pissed off at human abuse of damned near every part of her body, but especially forests and the interwoven ecologies of which they are an essential part. Of course, during hurricane/cyclone season - intensified by ocean warming - you might also say she's pissed off at human abuse (pollution) of oceans and seas. Whether humans are able to convert the earth into a completely artificial satellite of the sun - like Asimov's Trantor in his Foundation novels - remains to be seen. At this point, it seems more likely that we'll wipe out necessary conditions for human life as we are doing with those needed by many other species. What we don't burn, we flood; what we don't burn or flood, we poison. Of course that "we" is not you and me but capitalism that - in good Judeo-Christian and Muslim tradition - sees "nature" as made up of nothing more than resources for use in maintaining control over society.