North America Hazard Brief-Canada–United States Weekly Climate & Hazard Brief-September 21, 2026-What Has Changed in the Past Week
The clearest change this week is that the major summer wildfire emergency continues its seasonal decline, although the fire season is not finished. Canada now has 393 active wildfires, down from roughly 482 a week ago. Canada has recorded 5,372 fires and about 4.47 million hectares burned so far in 2026. This is a substantial reduction in active fires in just one week and confirms that cooler nights, shorter days, and early-autumn weather are beginning to change the national fire environment.
The United States is showing the same broad transition. NIFC reported suppressing 46 large fires on September 20, compared with 58 large fires in last week's briefing. National preparedness remains at Level 3, well below the Level 5 conditions of August. As of September 18, more than 12,000 personnel were still assigned to wildfires, however, and total U.S. acreage burned this year had reached approximately 8.52 million acres.
So there is genuine improvement. But this is best understood as a transition from the peak fire season rather than its complete ending. Northern regions are shutting down rapidly, while parts of British Columbia and the western United States can remain vulnerable to significant fire behaviour during warm, dry and windy autumn periods.
Wildfire — Observed Conditions
Observed: Canada's active-fire count has fallen by nearly 90 fires since last week's briefing. That is one of the strongest signs yet that the national season is turning. Nevertheless, almost 400 fires remain active, and provincial and territorial agencies remain the authoritative sources for rapidly changing local conditions.
In the United States, Northern California, the Northwest and Southern California remain at regional Preparedness Level 3, while the Northern Rockies, Great Basin and Rocky Mountain areas are at Level 2. Alaska, the Eastern Area and Southwest are at Level 1. This increasingly uneven geography is characteristic of the autumn transition: fire danger is retreating rapidly from some regions while remaining important in others.
The United States has now experienced an extraordinary fire year. NOAA reported this week that the contiguous United States experienced its warmest June–August on record, with below-normal precipitation and widespread drought helping sustain a destructive wildfire season.
How Much Longer Could the Fire Challenge Continue?
The answer is becoming clearer: for much of Canada and the northern United States, the worst of the 2026 fire season is probably behind us, but several weeks of meaningful fire potential remain farther west and south.
September progressively works in favour of firefighters. Nights become longer, temperatures generally fall, humidity recovery improves and vegetation loses less moisture each day. Autumn Pacific storms eventually provide the widespread soaking precipitation capable of ending major fire seasons across much of the Northwest and British Columbia.
But that transition does not occur everywhere simultaneously. Large established fires can continue burning in heavy timber and deep organic material long after surrounding fire danger has declined. A few warm, dry and windy days can also temporarily reactivate fires that appeared relatively quiet.
The regions requiring the closest fire watch through the remainder of September are therefore British Columbia, Washington, Oregon, northern and southern California and portions of the Great Basin and northern Rockies. Southern California can retain meaningful wildfire danger considerably later into autumn because its most dangerous fire weather can coincide with strong offshore winds later in the year.
The encouraging difference from August is that the overall continental environment is no longer moving steadily toward greater fire danger. It is now moving toward seasonal recovery. The question is how quickly sustained autumn moisture reaches the remaining dry landscapes.
Smoke — Observed Conditions
Observed: There is no comparable continent-wide smoke emergency this week to the episodes experienced during the height of summer. That is another important improvement accompanying the decline in wildfire activity.
Smoke remains possible around individual fire complexes, however, and valleys can experience significant overnight and morning concentrations when stable autumn air traps smoke close to the surface. Remote communities near persistent fires should therefore continue monitoring local air-quality guidance even when the immediate flame threat has diminished.
The distinction is important: the continental smoke burden is declining, but local smoke exposure has not disappeared.
Drought — The Hazard That Is Not Disappearing With Autumn
The wildfire season may be easing, but drought remains deeply established across large parts of North America.
NOAA reported on September 16 that nearly half of the contiguous United States remained in drought following the warmest June–August period on record. Major western reservoirs, including Lake Mead and Lake Powell, had fallen to record-low levels.
Conditions changed somewhat during the past week. Beneficial rainfall brought improvement to portions of the Plains, including substantial improvement in parts of Iowa. But extreme warmth and insufficient rainfall caused deterioration farther south and east. Texas and the Ark-La-Tex region have experienced particularly rapid drying, while drought also worsened across portions of the Southeast.
This is an important transition to recognize. Fire danger can decline seasonally while drought remains underneath it. Cooler autumn temperatures may suppress wildfire without restoring groundwater, reservoirs, streamflow or deep soil moisture.
Those unresolved moisture deficits will matter greatly when North America enters winter.
Extreme Heat — Forecast
Forecast: The broad extreme-heat emergency of July and August has now substantially diminished.
NOAA's latest Week-2 Hazards Outlook, valid September 28 through October 4, identifies no significant extreme-temperature hazard for the continental United States.
Individual regions can certainly still experience unusually warm autumn days, particularly where drought remains severe. But the continental-scale heat threat is clearly moving downward as solar intensity decreases and nights lengthen.
That is good news for both people and firefighters.
Flooding and Heavy Rain
The rainfall picture has become particularly interesting because parts of North America are beginning to demonstrate the transition from summer drought toward autumn storm systems.
During the past week, Arizona experienced significant flash-flood danger as heavy thunderstorms affected areas containing burn scars, slot canyons and already saturated ground. This again illustrates the connection between wildfire and flooding: a watershed transformed by fire can respond very differently when heavy rain subsequently arrives.
Forecast: Looking farther ahead to September 28–October 4, NOAA identifies the Florida Peninsula and adjacent Gulf region as the principal area to watch. A stalled frontal boundary combined with persistent easterly flow could produce periods of heavy rainfall during the week.
NOAA does not presently identify another major nationwide precipitation hazard during that period. That is relatively encouraging, although short-range thunderstorms and localized flash floods can still occur outside areas highlighted by a two-week outlook.
Hurricanes and Tropical Storms — An Important Change This Week
There is now an active Atlantic tropical storm, unlike last week's briefing.
Tropical Storm Fay is presently several hundred miles southwest of the Azores. As of September 21, Fay had weakened to maximum sustained winds of about 50 mph (85 km/h) and was moving slowly southward. The National Hurricane Center expects continued weakening, with Fay likely becoming a post-tropical remnant low within the next couple of days. There are no coastal watches or warnings, and NHC lists no land hazards from Fay.
More importantly for Canada and the United States, the National Hurricane Center currently expects no additional Atlantic tropical-cyclone formation during the next seven days.
So although an Atlantic tropical storm exists, there is presently no tropical-storm or hurricane threat to Canada or the continental United States.
That is reassuring, particularly because we remain within the climatological heart of Atlantic hurricane season.
Indigenous and Remote Communities
For Indigenous and remote communities, the gradual decline in wildfire activity represents an important transition from emergency response toward recovery.
The danger does not end when flames move away from a community. People returning home may encounter damaged electrical systems, compromised drinking water, destroyed buildings, unstable roads, smoke-contaminated homes, damaged hunting and gathering areas and altered forests and watersheds.
There is also a longer-term dimension. A severely burned watershed can remain unstable for months or years. Heavy autumn rainfall or spring snowmelt can produce erosion, debris flows and changes in water quality long after the original wildfire has disappeared.
For remote First Nations and Tribal communities, this means recovery planning should increasingly include watershed monitoring, drinking-water security, road and bridge inspection, clean indoor air, housing repair and mental-health and cultural supports, alongside conventional fire suppression.
This is also the moment to record what communities learned during the 2026 season while those experiences remain fresh: which evacuation routes worked, where communications failed, which Elders required additional assistance, whether clean-air shelters were sufficient, how medicines and animals were transported and what resources communities needed but could not obtain quickly.
Those lessons can become part of preparation for the next fire season rather than being rediscovered during the next emergency.
What to Watch: September 21–October 4
The first thing to watch is whether the wildfire decline becomes permanent for the season. Canada's active-fire count has now fallen to 393, and U.S. large-fire numbers continue declining. If widespread autumn moisture reaches British Columbia and the Pacific Northwest during the coming weeks, the northern 2026 fire season could move decisively toward its end.
The second issue is drought. The disappearance of summer heat does not mean the water deficit has disappeared. Nearly half of the contiguous United States remained in drought in mid-September, and significant moisture deficits remain across important agricultural and western regions.
The third issue is Florida and the Gulf region, where NOAA sees an elevated possibility of persistent heavy rainfall during September 28–October 4.
The fourth is the Atlantic. Tropical Storm Fay itself poses no North American threat and is weakening, while NHC currently expects no additional tropical development during the coming seven days. But hurricane season continues, so this must remain under weekly observation.
The larger picture this week is therefore more encouraging than it has been for several months. The continental wildfire emergency is genuinely easing. Extreme heat is retreating. Widespread smoke has diminished. No Atlantic tropical cyclone currently threatens Canada or the United States.
But the deeper conditions left behind by this extraordinary summer remain.
Millions of hectares and acres have burned. Large areas remain drought-stressed. Reservoirs and watersheds have been depleted. Burned landscapes will encounter autumn rain and eventually winter snow. Indigenous and remote communities that endured evacuation are beginning the much longer work of returning, repairing and restoring.
The emergency phase is slowly giving way to something equally important: recovery, healing of the land and preparation for what the next season will bring.