Wildfire smoke Likely
Daily PM2.5 peaked at 33.8 µg/m³ near Orlando across 2 covered metros home to 3.8 million people.
Counting the extra PM2.5 above each metro's typical day, this event handed the average affected resident ≈ 1.1 cigarettes. Across everyone living in the affected metros, that is the collective equivalent of ≈ 4.1 million cigarettes. An awareness illustration of outdoor exposure at 22 µg/m³ per cigarette (Berkeley Earth), counting only the event's ranked days; not a medical dose.
Why we think this happened
A contemporaneous wire report says dense wildfire smoke affected Florida on the exact event dates, closed Alligator Alley in southwest Florida, and describes crews fighting a 650-acre wildfire two miles from Disney property near Orlando. That directly covers both event geographies, although it does not provide monitor-level source apportionment.
Likely Applicable reporting or a supported inference makes this the best current causal explanation.
People's Daily / wire report corroborates
The report says dense wildfire smoke blanketed parts of Florida, Alligator Alley was closed by smoke during the event window, and crews were fighting a 650-acre wildfire two miles from Disney property near Orlando.
National Interagency Fire Center · May 18, 2001 hypothesis
The federal incident report records a fire in Orange County, Florida, on the event date and describes dry, warm conditions with very high to extreme Florida fire indices. It does not assess PM2.5 or establish that the fire affected Orlando or Fort Myers.
See every retained source and limitation ↓
Sequence: Orlando (May 18) → Cape Coral (May 19)
Evidence path
A cause is more convincing when the record connects three things: something happened, the air mass moved toward the region, and local instruments responded. Here is how much of that chain is documented for this event.
Source or mechanism
The report says dense wildfire smoke blanketed parts of Florida, Alligator Alley was closed by smoke during the event window, and crews were fighting a 650-acre wildfire two miles from Disney property near Orlando.
View supporting source ↗Air-mass movement
The retained record does not yet show how air traveled from the proposed source to these metros. A trajectory replay or dated plume analysis belongs here.
Local response
The federal incident report records a fire in Orange County, Florida, on the event date and describes dry, warm conditions with very high to extreme Florida fire indices. It does not assess PM2.5 or establish that the fire affected Orlando or Fort…
Inspect the pollutant and weather signals ↓Event autopsy
Before, during, and after the episode: nearby pollutant monitors and surface-weather stations show what changed. This context tests the “Wildfire smoke” explanation; it does not assign the cause by itself.
Orlando-Kissimmee-Sanford, FL
Monitor comparison window 2001-05-15 to 2001-05-22 · PM2.5 target: Primrose Ave
36% above nearby days
About the same as surrounding days
36% higher than surrounding days
About the same as surrounding days
29% higher than surrounding days
32% higher than surrounding days
10% higher than surrounding days
About the same as surrounding days
Cape Coral-Fort Myers, FL
Monitor comparison window 2001-05-15 to 2001-05-22 · PM2.5 target: Winkler Pump Station
39% above nearby days
16% higher than surrounding days
39% higher than surrounding days
16% higher than surrounding days
About the same as surrounding days
Source: U.S. EPA AirData daily observations and, where available, nearby ASOS/AWOS surface observations. Values are descriptive medians over the retained monitor set; missing measurements remain missing. Transport and source evidence remain separate layers because this instrument pattern does not assign a cause by itself.
Episode peak
-- cigarettes
The smoke map's scale, replayed over this event: the surface interpolates between covered metros' daily records, framed to the affected region. Hover for a reading, click a metro to pin it to the card. Days a monitor did not report draw nothing.
Views from the selected metro
Select a metro on the map to see nearby cameras. Where an operator archive reaches the event, drag the divider to compare two moments, adjust either date and time, or play the available event-day frames. Camera imagery is visual context, not an air-quality measurement or proof of smoke.
No useful public camera views are currently available within 80 km of this metro.
| Metro | Peak PM2.5 | Cigarettes, whole event | Peak day | All-time standing |
|---|---|---|---|---|
| Orlando-Kissimmee-Sanford, FL | 33.8 µg/m³ | 1.5 | May 18, 2001 | #20 of its top days |
| Cape Coral-Fort Myers, FL | 21.4 µg/m³ | 1.0 | May 19, 2001 | #20 of its top days |
"Cigarettes, whole event" totals a metro's ranked event days at 22 µg/m³ per cigarette: what a person outdoors there breathed across the event, as the illustration. "All-time standing" is where this episode's days sit in each metro's ranked record (worst-area measure, since 1999). Full local context is on each metro's Air Records page.
Public evidence library
Each card states what a source supports—and what it does not. Official records, research, reporting, community observations, and transparent inferences remain visibly different kinds of evidence.
People's Daily / wire report
The report says dense wildfire smoke blanketed parts of Florida, Alligator Alley was closed by smoke during the event window, and crews were fighting a 650-acre wildfire two miles from Disney property near Orlando.
A retained source supports the attributed cause for the stated place and dates.
The wire report does not quantify the wildfire contribution at either regulatory monitor.
Likely Applicable reporting or a supported inference makes this the best current causal explanation.
This episode was grouped from the monitor record by the catalog pipeline and given its cause from the evidence listed above. It has not been individually reviewed and signed off, so its boundaries, cause, and name may change as evidence accumulates. Grouping policy common_sense_root_cause_grouping.v2. The cause label reflects the assembled evidence above, not an IAQng detection formula. If it is wrong, tell us.