Dense Smoke
NOAA Storm Events type · 147 records since 2006 · 17 states and territories
The National Weather Service defines dense smoke as: "Dense smoke, reducing visibilities to values equal to or below locally/regionally established values (usually ¼ mile or less), that adversely affects people and/or impacts transportation or commerce." NOAA's Storm Events Database holds 147 dense smoke records from 2006 through June 30, 2026, the most in North Dakota (36), with 2 deaths recorded.
How the National Weather Service files dense smoke
Dense smoke, reducing visibilities to values equal to or below locally/regionally established values (usually ¼ mile or less), that adversely affects people and/or impacts transportation or commerce. If the event that occurred is considered significant, even though it affected a small area, it should be entered into Storm Data.
National Weather Service Instruction 10-1605, Storm Data Preparation (July 26, 2021), Appendix A, entry 8
Source: National Weather Service Instruction 10-1605. Read the instruction (PDF).
Dense Smoke, 2006 to 2026
Records per year (2026 to June 30, 2026).
- recorded, no damage figure
- under $10 million
- $10 million or more
- $100 million or more
- $1 billion or more, or 100 deaths
- $10 billion or more, or 1,000 deaths
- a year's colour: its recorded damage or deaths
- a year with a death
- Records
- 1472006 to June 30, 2026
- Deaths
- 217 injuries
- Damage, 2025 dollars
- $180Kas filed (scale steps before 1993)
- Counties with a record
- 123of 3,266
Source: NOAA NCEI Storm Events Database, records through June 30, 2026. Search the record at NCEI.
Where do dense smoke records happen?
States
Counties
Source: NOAA NCEI Storm Events Database (forecast-zone records count on every county the zone covers).
When do dense smoke records happen?
40% of its dense smoke records since 2006 fell in August and September. The busiest month is May.
The values, month by month
Jan 4 · Feb 0 · Mar 4 · Apr 1 · May 41 · Jun 5 · Jul 3 · Aug 29 · Sep 30 · Oct 3 · Nov 26 · Dec 1 (records).
Source: NOAA NCEI Storm Events Database, records by the month they began.
The deadliest dense smoke records
| Date | Record | Character | Killed | Injured | Damage |
|---|---|---|---|---|---|
| 2012-08-18 | Dense SmokeJasper County, IN · forecast zone Jasper At least 20 vehicles were involved in three separate accidents along a two-mile stretch centered near mile marker 227 on Interstate 65. One indirect fatality and at least four indirect injuries were reported. The wrecks were attributed to smoke from a nearby farm and possibly fog reducing visibility to less than 30 ... | 1 | 4 | – | |
| 2015-03-28 | Dense SmokeStillwater County, MT · forecast zone Northern Stillwater A multi-vehicle crash occurred on Interstate 90. A woman from Park City, Montana was killed after blowing smoke mixed with dirt/dust created zero visibility. The crash involved five vehicles and injured several people around 3 pm. According to the Montana Highway Patrol , speed and low visibility played a significant ... | 1 | 0 | – |
Source: NOAA NCEI Storm Events Database, deaths direct and indirect as filed.
The most recent dense smoke records
| Date | Record | Character | Killed | Injured | Damage |
|---|---|---|---|---|---|
| 2015-03-28 | Dense SmokeStillwater County, MT · forecast zone Northern Stillwater | 1 | 0 | – | |
| 2012-08-18 | Dense SmokeJasper County, IN · forecast zone Jasper | 1 | 4 | – | |
| 2008-01-07 | Dense SmokeBladen County, NC · forecast zone Bladen | 0 | 3 | – | |
| 2007-11-05 | Dense SmokeKlamath County, OR · forecast zone Klamath Basin | 0 | 10 | $142K |
Source: NOAA NCEI Storm Events Database.