Massachusetts air quality today

Every Massachusetts metro we track

Sun over Massachusetts today

The strongest UV in Massachusetts today is 7 (High) in Boston, arriving around 12pm local time. The mildest of the 2 metros we model here peaks at 7 in Worcester.

UV is modelled, not measured — unlike the AQI above it, which comes off an instrument. Hour by hour in Boston →

What stands behind these Massachusetts numbers

2 of the 2 metros here report from a named regulatory monitor — Boston Metro, Worcester. The dominant pollutant across Massachusetts today is PM2.5 in some metros, O3 in others.

We track 2 metropolitan areas in Massachusetts, not the whole state, and none of them has its own page yet — a metro page ships only after thirty days of our own history, and that clock is running. There is no state-wide average here on purpose: averaging 2 metros into one figure would invent a value for all the ground between them. How we measure, and what we refuse to estimate →

Neighbouring states

Smoke and inversions do not stop at a state line, so when Massachusetts looks wrong the answer is often next door.