How Bad Was The Air In Minnesota? Here's The Cigarette Comparison

TWIN CITIES, MN — Air pollution in parts of Minnesota this week briefly reached levels that, if sustained over a full day, would be the health equivalent of smoking more than 20 cigarettes, according to pollution exposure models.

Between June 2 and 4, a thick wave of wildfire smoke swept across the state, pushing fine particle pollution to record-breaking levels.

In Grand Portage, the air hit 476.2 micrograms per cubic meter (µg/m³) of fine particulate matter, the highest wildfire smoke reading ever recorded at a state regulatory monitor, according to the Minnesota Pollution Control Agency (MPCA).

Researchers at Berkeley Earth estimate that breathing 22 µg/m³ over 24 hours is about equal in health impact to smoking one cigarette.

That means if Grand Portage’s pollution level of 476 µg/m³ had persisted for 24 hours, it would have been roughly equivalent to smoking 21 cigarettes in a day, according to Berkeley Earth’s air quality model.

St. Cloud, Red Lake Nation, Leech Lake Nation, and Brainerd — all above 400 µg/m³ — suffered similar toxicity.

The MPCA says this was one of the worst wildfire smoke events since it began tracking them in 2013.

The list below shows the top hourly smoke readings in Minnesota history, including more than a dozen cities that reached "very unhealthy" levels this week alone.

(And yes — the highest hourly pollution level ever recorded in Minnesota still belongs to fireworks: a 657 µg/m³ spike in Minneapolis on July 4, 2020.)

GREATER MINNESOTA

• 476.2 – Grand Portage – 2 a.m. 6/3/2025 (new state record)
• 422.0 – St. Cloud – 8 a.m. 7/29/2021
• 416.6 – Red Lake Nation – 2 p.m. 6/2/2025
• 407.3 – Leech Lake Nation – 4 p.m. 6/2/2025
• 401.1 – Brainerd – 5 a.m. 7/29/2021
• 397.0 – Red Lake Nation – 2 a.m. 7/20/2021
• 383.9 – Detroit Lakes – 7 p.m. 6/2/2025
• 338.5 – Leech Lake Nation – 7 a.m. 7/20/2021
• 330.8 – Fargo – 2 p.m. 7/29/2021
• 291.6 – Red Lake Nation – 2 p.m. 7/29/2021
• 288.0 – St. Cloud – 9 p.m. 5/6/2016
• 266.4 – Virginia – 6 p.m. 9/3/2021
• 260.0 – Fargo – 12 p.m. 7/20/2021
• 243.1 – Leech Lake Nation – 1 p.m. 6/2/2025
• 236.5 – Fargo – 12 a.m. 7/21/2021

TWIN CITIES METRO

• 353.0 – St. Michael – 1 a.m. 5/7/2016
• 285.0 – Minneapolis - Phillips – 1 a.m. 5/7/2016
• 285.0 – Minneapolis – 1 a.m. 5/7/2016
• 267.0 – St. Michael – 1 p.m. 7/29/2021
• 260.0 – Blaine – 1 a.m. 5/7/2016
• 234.0 – Lakeville – 2 a.m. 5/7/2016
• 231.5 – Apple Valley – 6 p.m. 6/14/2023
• 230.0 – Minneapolis – 2 p.m. 6/14/2023
• 230.0 – St. Paul - Harding H.S. – 5 p.m. 6/14/2023
• 228.0 – Lakeville – 8 p.m. 6/14/2023
• 224.0 – Apple Valley – 1 p.m. 6/15/2023
• 219.0 – Minneapolis - Phillips – 5 p.m. 6/14/2023
• 203.6 – Blaine – 6 a.m. 6/3/2025
• 199.8 – Apple Valley – 2 a.m. 5/7/2016
• 198.0 – Shakopee – 7 p.m. 6/14/2023
• 197.3 – Lakeville – 1 p.m. 6/15/2023
• 197.3 – Minneapolis - Pacific St. – 6 a.m. 6/3/2025
• 197.3 – Minneapolis - Phillips – 6 a.m. 6/3/2025

The good news? For now, there are no smoke events in the current NWS forecast.

Here's the full NWS forecast from the Minneapolis-St. Paul Airport:

Today: A 10 percent chance of showers and thunderstorms after 5pm. Partly sunny, with a high near 80. South wind around 5 mph.

Tonight: A 50 percent chance of showers and thunderstorms, mainly after 8pm. Mostly cloudy, with a low around 61. South wind around 5 mph becoming calm after midnight. New rainfall amounts of less than a tenth of an inch, except higher amounts possible in thunderstorms.

Friday: Showers likely, with thunderstorms also possible after 1pm. Mostly cloudy, with a high near 72. Northeast wind around 5 mph. Chance of precipitation is 60%. New rainfall amounts of less than a tenth of an inch, except higher amounts possible in thunderstorms.

Friday Night: A slight chance of showers and thunderstorms, then a chance of showers after 10pm. Partly cloudy, with a low around 55. East northeast wind around 5 mph. Chance of precipitation is 30%.

Saturday: A slight chance of showers, then a chance of showers and thunderstorms after 1pm. Mostly sunny, with a high near 75. East southeast wind 5 to 10 mph becoming south in the afternoon. Chance of precipitation is 40%.

Saturday Night: A chance of showers and thunderstorms, then showers and possibly a thunderstorm after 1am. Low around 57. South wind around 10 mph becoming west after midnight. Chance of precipitation is 80%. New rainfall amounts between a tenth and quarter of an inch, except higher amounts possible in thunderstorms.

Sunday: A slight chance of showers and thunderstorms before 7am, then a slight chance of showers between 7am and 1pm, then a chance of showers and thunderstorms after 1pm. Mostly sunny, with a high near 71. West northwest wind 10 to 15 mph, with gusts as high as 25 mph. Chance of precipitation is 50%.

Sunday Night: A 40 percent chance of showers and thunderstorms. Mostly cloudy, with a low around 52. West wind 10 to 15 mph.

Monday: A chance of showers, then showers likely and possibly a thunderstorm after 1pm. Partly sunny, with a high near 68. Northwest wind 10 to 15 mph. Chance of precipitation is 60%.

Monday Night: A 20 percent chance of showers and thunderstorms before 1am. Partly cloudy, with a low around 53. Northwest wind 5 to 10 mph.

Tuesday: Mostly sunny, with a high near 76. West northwest wind 5 to 10 mph.

Tuesday Night: Mostly clear, with a low around 57. West wind 5 to 10 mph becoming south after midnight.

Wednesday: Sunny, with a high near 82. South southwest wind 5 to 10 mph