MMWR week 38 · Week ending Sep 26, 2026
Flu activity this week
How much flu is circulating in the United States right now, measured four ways: outpatient visits, lab tests, hospital admissions, and CDC's state activity levels. Updated every Friday after CDC publishes FluView.
The 2026–27 flu season starts with MMWR week 40, the week ending October 10, 2026.
Until those numbers arrive, the charts below show the full 2025–26 season against earlier seasons. Off-season activity is normally low; a rise in late September or October is the first sign the new season is under way.
Activity level by state
CDC's acute respiratory illness (ARI) activity level compares each state's share of emergency department visits for respiratory illness with its own past seasons. Select a state for its full history.
Week ending Sep 26, 2026. CDC publishes only the current week of this measure; FluHub archives each week so the history builds over the season.
Activity levels reflect all acute respiratory illness, which includes COVID-19 and RSV as well as flu. Pair them with the lab percent-positive figure to see how much is influenza.
The national flu curve
Each line is one flu season, aligned on the same calendar weeks from October through September, so you can see whether this season is early, late, higher, or lower than usual.
- 2025–26 season
- 2024–25 season
- Typical range, 2010–11 to 2024–25 (10th–90th percentile)
- Typical median
Influenza-like illness is fever with cough or sore throat. Shaded band shows the 10th to 90th percentile of past seasons, excluding 2020–21 and 2021–22, when COVID-19 measures suppressed flu. The dashed line is CDC's national baseline: activity above it marks the flu season.
- 2025–26 season
- 2024–25 season
- Typical range, 2016–17 to 2024–25 (10th–90th percentile)
- Typical median
Percent positive is the most flu-specific of the weekly measures; it rises before hospital admissions do.
- 2025–26
- 2024–25
- Earlier seasons
Hospitals have been required to report respiratory admissions to CDC's National Healthcare Safety Network since November 2024; earlier weeks reflect voluntary or differently mandated reporting, so small differences across seasons should not be over-read.
Every state, this week
Select a column header to sort. The trend line covers the last 16 weeks of outpatient flu-like illness.
| State | Activity level | Flu-like illness | vs prior wk | Lab % positive | Admits per 100k | 16 weeks |
|---|---|---|---|---|---|---|
| Alabama | Low | 1.6% | +0.0 | 0.8% | 0.73 | |
| Alaska | Very Low | 0.0% | −1.9 | – | 2.11 | |
| Arizona | Very Low | 1.6% | +0.1 | 0.9% | 0.38 | |
| Arkansas | Very Low | 1.1% | −0.1 | 2.4% | 0.33 | |
| California | Very Low | 2.6% | +0.0 | 8.0% | 0.99 | |
| Colorado | Very Low | 1.8% | +0.0 | 3.5% | 0.55 | |
| Connecticut | Very Low | 1.4% | −0.2 | – | 0.25 | |
| Delaware | Very Low | 0.6% | +0.1 | – | 0.00 | |
| District of Columbia | Very Low | 2.2% | −0.5 | – | 0.44 | |
| Florida | Very Low | 2.7% | +0.3 | 4.5% | 1.82 | |
| Georgia | Very Low | 2.1% | −0.1 | 1.5% | 0.26 | |
| Hawaii | Very Low | 2.3% | −0.3 | – | 2.01 | |
| Idaho | Very Low | 1.7% | +0.2 | 0.0% | 0.61 | |
| Illinois | Very Low | 0.9% | +0.0 | 0.0% | 0.49 | |
| Indiana | Very Low | 1.3% | +0.1 | 0.8% | 0.55 | |
| Iowa | No data | 0.4% | +0.2 | 1.3% | 0.28 | |
| Kansas | Very Low | 0.8% | +0.1 | – | 0.21 | |
| Kentucky | Very Low | 0.7% | +0.1 | – | 0.38 | |
| Louisiana | Very Low | 2.6% | +0.5 | – | 1.12 | |
| Maine | Very Low | 0.7% | +0.2 | 5.2% | 0.36 | |
| Maryland | Very Low | 1.3% | −0.0 | 2.0% | 0.33 | |
| Massachusetts | Very Low | 1.3% | +0.1 | 2.4% | 0.16 | |
| Michigan | Very Low | 1.0% | +0.1 | 0.8% | 0.39 | |
| Minnesota | Very Low | 1.0% | +0.2 | 2.5% | 0.37 | |
| Mississippi | Very Low | 1.9% | +0.0 | – | 0.75 | |
| Missouri | Very Low | 1.0% | −0.1 | 1.5% | 0.55 | |
| Montana | Very Low | 0.5% | −0.1 | 6.9% | 2.57 | |
| Nebraska | Very Low | 0.8% | −0.2 | 3.4% | 0.10 | |
| Nevada | Very Low | 1.6% | +0.1 | 8.4% | 1.29 | |
| New Hampshire | Low | 0.7% | +0.2 | – | 0.29 | |
| New Jersey | Very Low | 3.4% | +0.7 | 1.4% | 0.78 | |
| New Mexico | Very Low | 1.6% | −0.1 | 2.1% | 0.43 | |
| New York | Very Low | 2.4% | +0.0 | – | 0.49 | |
| North Carolina | Very Low | 1.4% | +0.0 | 0.8% | 0.47 | |
| North Dakota | Very Low | 0.3% | −0.1 | 2.5% | 0.64 | |
| Ohio | Low | 1.7% | +0.2 | 0.5% | 0.42 | |
| Oklahoma | Very Low | 0.6% | −0.5 | – | 0.27 | |
| Oregon | Very Low | 1.2% | −0.0 | – | 0.78 | |
| Pennsylvania | Very Low | 1.1% | +0.1 | 0.8% | 1.34 | |
| Rhode Island | Very Low | 1.1% | −0.6 | – | 0.27 | |
| South Carolina | Very Low | 2.3% | +0.0 | 2.8% | 0.60 | |
| South Dakota | Very Low | 0.6% | −0.0 | – | 0.11 | |
| Tennessee | Very Low | 1.7% | +0.1 | – | 0.90 | |
| Texas | Very Low | 1.8% | −0.1 | 3.5% | 0.82 | |
| Utah | Very Low | 0.2% | −0.0 | – | 0.53 | |
| Vermont | Very Low | 0.9% | −0.1 | 1.7% | 0.31 | |
| Virginia | Very Low | 1.9% | +0.1 | 2.3% | 0.44 | |
| Washington | Very Low | 1.7% | +0.2 | 8.3% | 1.39 | |
| West Virginia | Very Low | 0.5% | −2.3 | 0.8% | 0.23 | |
| Wisconsin | Very Low | 0.8% | +0.1 | 3.1% | 0.58 | |
| Wyoming | Low | 2.6% | +0.5 | 0.0% | 0.52 |
State flu-like illness is unweighted %ILI from providers in that state. A dash means the state did not report that week or the measure is not published for it.
Sources: CDC Level of Acute Respiratory Illness (ARI) Activity by State; CDC ILINet (U.S. Outpatient Influenza-like Illness Surveillance Network), via Delphi Epidata API; WHO Collaborating Laboratories and NREVSS, clinical laboratories, via Delphi Epidata API; CDC NHSN Weekly Hospital Respiratory Data (HRD) Metrics by Jurisdiction. All surveillance data are preliminary and revised as late reports arrive. Retrieved Oct 5, 2026.