When Does Flu Season End? 2025-2026 Season Timeline

When Does Flu Season End in 2026?

The short answer: flu season in the United States typically ends between April and May, but the timing varies by year and by state. The 2025-2026 season peaked around January and has been declining since, but flu is still circulating in many states.

Where Flu Is Still Active

As of early April 2026, several states continue to show moderate flu activity. Check any state’s current status on our flu activity map:

States to watch:

Oregon flu activity — Consistently elevated this season
Louisiana flu activity — Southern states often have longer tails
Alabama flu activity — Still seeing outpatient visits
Illinois flu activity — Midwest declining but active
Kentucky flu activity — Borderline moderate

How Do We Know When Flu Season Is Over?

The CDC doesn’t declare an official “end” to flu season. Instead, we watch for ILI (influenza-like illness) rates to drop below baseline levels — typically around 2% of outpatient visits nationally. When most states are in the “Low” activity range for several consecutive weeks, the season is effectively over.

You can track this in real time on our national flu dashboard, which shows the week-by-week trend and how many states are at each activity level.

Historical Timing

Based on past seasons:

2024-2025: Activity dropped to baseline in late April
2023-2024: Longer season, baseline reached in May
2022-2023: Early peak (November), baseline by March

The 2025-2026 season appears to be tracking toward a late April to early May end for most states.

What Comes After Flu Season?

Once flu winds down, the main respiratory threats shift:

COVID-19 continues year-round with seasonal surges — check our COVID-19 dashboard
RSV has already ended its season for most states — see RSV data
Summer illnesses (enterovirus, hand-foot-mouth) are not tracked on this site

Stay Informed

We update flu data every Friday from the CDC’s ILINet surveillance network. Bookmark your state’s flu page or check our blog for weekly analysis.

Updated weekly. Last update: April 3, 2026.