Hartford Air Quality in January

Across 2019–2025, Hartford's January air quality had a median AQI of 39 (Good) over 217 monitored days in the Hartford-West Hartford-East Hartford, CT area. 0.0% of January days (0 of 217) reached Unhealthy for Sensitive Groups or worse, and fine particulate matter (PM2.5) set the daily AQI on 63.6% of days. The cleanest January on record here was 2023 (median AQI 33, 0 days above 100) and the worst was 2022 (median 53, 0 days above 100, peak AQI 80).

39
Median AQI
Good
0.0%
Days above AQI 100
0 of 217 days
61
90th percentile AQI
worst 1 day in 10
93
Peak AQI
Moderate
PM2.5
Main pollutant
63.6% of days
64.1%
Good days
139 of 217
  • Good: 64.1%
  • Moderate: 35.9%
  • Unhealthy for Sensitive Groups: 0.0%
  • Unhealthy or worse: 0.0%

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QUICK ANSWER

How is the air in Hartford in January?

Good on a typical day: median AQI 39 across 2019–2025, with 0.0% of January days above AQI 100. Fine particulate matter (PM2.5) is the main driver.

  • 64.1% of January days were Good (AQI 0–50), 35.9% Moderate (51–100).
  • 0 days of 217 reached AQI 101+; the January peak was 93.
  • Best January: 2023; worst January: 2022.

Frequently asked questions

What is the air quality like in Hartford in January?

Across 2019–2025, the median daily AQI in Hartford in January was 39 (Good). 64.1% of days were Good, 35.9% Moderate, and 0.0% reached Unhealthy for Sensitive Groups or worse, based on 217 monitored days in EPA's Air Quality System.

Is January a good time for outdoor exercise in Hartford?

A typical January day in Hartford sits in the Good range (median AQI 39), so running, cycling and children's outdoor play are fine for everyone on most days; fewer than 1% of January days reached AQI 101+ in 2019–2025.

Which pollutant causes Hartford's January air quality problems?

Fine particulate matter (PM2.5) set the daily AQI on 63.6% of January days in Hartford. The highest January AQI recorded in 2019–2025 was 93 (Moderate), in 2022.

Hartford January air quality, year by year

Hartford January air quality by year (Hartford-West Hartford-East Hartford, CT, EPA AQS daily AQI)

YearDays monitoredMedian AQIDays above 100Peak AQIMain pollutant
20193141062PM2.5
20203145084PM2.5
20213139093PM2.5
2022worst3153080PM2.5
2023cleanest3133062PM2.5
20243135067PM2.5
20253134071O3

What January air means in Hartford

A typical January day in Hartford sits in the Good range (median AQI 39), so running, cycling and children's outdoor play are fine for everyone on most days; fewer than 1% of January days reached AQI 101+ in 2019–2025.

January's median AQI of 39 is below Hartford's whole-year median of 43, making it one of the area's cleaner periods. Nationally, the median January AQI across every EPA metro area (95,602 metro-days, 2019–2025) is 39, so Hartford runs in line with the national January norm; 0.0% of its January days topped AQI 100 versus 0.7% nationally (about the same).

January is part of Hartford's winter season (December, January, February); the winter page pools all three months.

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

Right now in Hartford

The latest EPA AirNow observation puts Hartford's AQI at 36 (PM2.5). The figures above are multi-year month statistics, not today's reading.

View current Hartford air quality →

Source: EPA Air Quality System (AQS) pre-generated Daily AQI by CBSA files — daily AQI by CBSA (Hartford-West Hartford-East Hartford, CT), 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.