Toledo Air Quality in May

Across 2019–2025, Toledo's May air quality had a median AQI of 46 (Good) over 217 monitored days in the Toledo, OH area. 3.2% of May days (7 of 217) reached Unhealthy for Sensitive Groups or worse, and ground-level ozone set the daily AQI on 73.3% of days. The cleanest May on record here was 2025 (median AQI 42, 0 days above 100) and the worst was 2021 (median 46, 4 days above 100, peak AQI 122).

46
Median AQI
Good
3.2%
Days above AQI 100
7 of 217 days
74
90th percentile AQI
worst 1 day in 10
122
Peak AQI
Unhealthy for Sensitive Groups
O3
Main pollutant
73.3% of days
63.6%
Good days
138 of 217
  • Good: 63.6%
  • Moderate: 33.2%
  • Unhealthy for Sensitive Groups: 3.2%
  • Unhealthy or worse: 0.0%

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QUICK ANSWER

How is the air in Toledo in May?

Good on a typical day: median AQI 46 across 2019–2025, with 3.2% of May days above AQI 100. Ground-level ozone is the main driver.

  • 63.6% of May days were Good (AQI 0–50), 33.2% Moderate (51–100).
  • 7 days of 217 reached AQI 101+; the May peak was 122.
  • Best May: 2025; worst May: 2021.

Frequently asked questions

What is the air quality like in Toledo in May?

Across 2019–2025, the median daily AQI in Toledo in May was 46 (Good). 63.6% of days were Good, 33.2% Moderate, and 3.2% reached Unhealthy for Sensitive Groups or worse, based on 217 monitored days in EPA's Air Quality System.

Is May a good time for outdoor exercise in Toledo?

A typical May day in Toledo sits in the Good range (median AQI 46), so running, cycling and children's outdoor play are fine for everyone on most days; about 1 day in 31 of May days (3.2%) reached AQI 101+ in 2019–2025.

Which pollutant causes Toledo's May air quality problems?

Ground-level ozone set the daily AQI on 73.3% of May days in Toledo. The highest May AQI recorded in 2019–2025 was 122 (Unhealthy for Sensitive Groups), in 2021.

Toledo May air quality, year by year

Toledo May air quality by year (Toledo, OH, EPA AQS daily AQI)

YearDays monitoredMedian AQIDays above 100Peak AQIMain pollutant
20193144067PM2.5
20203143056O3
2021worst31464122O3
202231461112O3
202331512108O3
20243158087O3
2025cleanest3142084O3

What May air means in Toledo

A typical May day in Toledo sits in the Good range (median AQI 46), so running, cycling and children's outdoor play are fine for everyone on most days; about 1 day in 31 of May days (3.2%) reached AQI 101+ in 2019–2025.

May's median AQI of 46 is in line with Toledo's whole-year median of 45, so this period is neither a clean nor a dirty stretch for the area. Nationally, the median May AQI across every EPA metro area (104,064 metro-days, 2019–2025) is 44, so Toledo runs in line with the national May norm; 3.2% of its May days topped AQI 100 versus 1.3% nationally (above average).

May is part of Toledo's spring season (March, April, May); the spring page pools all three months.

Activity-specific thresholds: running, cycling, kids' sports.

Right now in Toledo

The latest EPA AirNow observation puts Toledo's AQI at 33 (PM2.5). The figures above are multi-year month statistics, not today's reading.

View current Toledo air quality →

Source: EPA Air Quality System (AQS) pre-generated Daily AQI by CBSA files — daily AQI by CBSA (Toledo, OH), 2019–2025. Daily AQI per CBSA is the highest AQI reported by any monitor in the area that day; the defining parameter is the pollutant that set it. Month and season statistics pool every such day in the period across all years listed. Retrieved 2026-09-09.