Flu season in New England: Cold winters, college campuses, and a January peak
New England has two flu seasons happening at the same time: the dense, fast-moving Boston metro and the quieter, lagging rural north. When flu hits Boston, it spreads fast through universities, commuter rail, and office corridors — and the numbers show it within two weeks. Maine, New Hampshire, and Vermont often run a week or two behind, with smaller populations that buffer initial spread. By January, the gap closes.
Current flu activity — HHS Region 1
This data is pulled live from the Delphi CMU Epidata API, which mirrors CDC FluView ILINet data for HHS Region 1. It reflects the most recent week available — typically data through the prior Saturday, published by the CDC the following Thursday.
States in HHS Region 1
HHS Region 1 covers Connecticut, Maine, Massachusetts, New Hampshire, Rhode Island, and Vermont. These states are grouped together by the Department of Health and Human Services for federal health program administration, and the CDC uses the same regional boundaries for flu surveillance reporting. ILI activity data is aggregated across all ILINet providers in the region, so the number reflects the regional average — individual states can vary significantly.
When flu typically peaks here
New England's flu season follows the national calendar closely, with a peak that typically falls in mid-to-late January. The season usually begins showing up in ILINet data in November, accelerates after Thanksgiving, and reaches its high point during the second and third weeks of January.
College calendars drive some of the region's early-season amplification. Boston-area universities — which include some of the country's densest student populations — return from winter break in early January, which reliably shows up in the ILI numbers 10–14 days later. In H3N2-dominant years, New England tends to peak earlier and harder than the national average; H1N1-dominant seasons are closer to typical.
The northern states lag the Boston metro by one to two weeks on average. If the map shows activity rising in Massachusetts but still Low in Maine, that gap typically closes within a fortnight.
What drives New England flu patterns
Boston's transit and density. The MBTA carries nearly 400,000 daily riders, making it one of the most efficient flu-transmission systems in the country. The city's commuter network pulls workers in from a 50-mile radius, distributing viruses across every suburban county in eastern Massachusetts and into Rhode Island and Connecticut.
College population concentration. Greater Boston has more college students per capita than almost any comparable metro area. Dormitories and shared dining halls are ideal transmission environments, and the January return from winter break reliably shows up in the data. The effect is measurable enough that flu coordinators track it as a leading indicator.
Older rural population in the north. Vermont, Maine, and New Hampshire have among the oldest median ages in the country. The same seasonal flu that causes moderate illness in younger adults can produce more hospitalizations in older populations — which means the northern states punch above their weight in terms of healthcare burden even when ILI percentages look modest.
Cold and dry winters. New England winters are textbook flu conditions: cold, low humidity, prolonged indoor crowding. The flu virus survives longer in dry air, and people spend more time in enclosed spaces from November through March. There's a reason this region rarely misses a season.
Recent seasons in HHS Region 1
Regional peak timing and severity can vary substantially from the national picture. The table below shows Region 1-specific peak months and severity for recent seasons, based on CDC FluView regional ILI data.
| Season | Regional peak | Dominant strain | Severity | Notable |
|---|---|---|---|---|
| 2024–25 | January | H3N2 / H1N1 | High | Above-average; dual A subtypes; Boston metro peaked week 3 |
| 2023–24 | January–February | H1N1 | Moderate | Moderate season; vaccine well-matched; late peak in northern states |
| 2022–23 | December | H3N2 | High | Early, severe; Boston hit in December ahead of national peak |
| 2021–22 | February–March | H3N2 | High | Compressed post-COVID season; late peak; young adults hard hit |
| 2019–20 | January | H1N1 | High | Season ended abruptly in March with COVID measures |
The best New England flu signal is the Massachusetts ILI report, which Delphi mirrors weekly. When Massachusetts crosses into Moderate, Connecticut and Rhode Island typically follow within 7–10 days, and the northern states within 2–3 weeks. The homepage tracks your region automatically. →
How to use this data
The live activity level above reflects the most recent week of CDC ILINet data for Region 1. There is always roughly a one-week lag between real-world conditions and published numbers — providers report weekly, the CDC publishes Thursdays, and this page reflects those numbers. During a rapidly rising season, treat the current level as a floor.
The ILI percentage is the share of outpatient visits attributed to influenza-like illness across all ILINet reporting providers in the region. It is not a case count and does not capture people who don't seek care. In regions with lower healthcare utilization rates (rural areas, communities with limited access), ILI percentages tend to understate true community activity.
For the most complete picture of the current season — including strain typing, lab positivity trends, and hospitalization data — the IsItFluSeasonYet homepage shows all of this in context. The regional activity shown here is the same data source as the homepage's region breakdown.