Flu season is here: How UK businesses can prepare for winter absence spikes

Every year, winter hits UK workplaces hard, but the 2025/26 season could be the toughest yet. According to the latest Chartered Institute of Personnel and Development (CIPD) Health and Wellbeing at Work 2025 report, UK employees took an average of 9.4 sick days last year—the highest in over a decade.

For UK businesses, this matters. Because this year, you’re facing a triple-threat scenario:

• The traditional flu and respiratory illness season

• A rise in mental health related absence and seasonal affective dips

• A surge in caregiving and family-related absence pressures (from childcare, school illness, etc)

These combine to create tangible business risks: lost productivity, scheduling strain, unplanned overtime and increased cost per absence. Use this post as your playbook to shift from reactive firefighting to proactive preparation.

Why winter absence peaks are a predictable business challenge

When winter comes, certain absence patterns repeat themselves. Knowing what to expect ahead of time lets you build resilient HR strategies rather than scramble at the first wave of sick leave.

The costs add up: more cover, temporary staff or overtime, disruption to project schedules, slower decision-making and potential morale dips in teams stretched thin. Over the winter months, these escalate more quickly than summer.

What the data tells us about seasonal absence patterns

Flu and respiratory illnesses lead the surge

Winter-time respiratory infections remain the classic driver of absence peaks. As the UK heads into the December–February window, expect pressure from colds, flu, bronchitis and other contagious illnesses to rise. According to UKHSA’s National Flu & COVID-19 Surveillance Report, flu-positivity has risen (6.1 %), and most strikingly the hospital-admission rate has climbed to 1.73 per 100,000 (up from 1.29).

Mental health and seasonal affective disorder (SAD) rise too

Shorter days, colder weather, increased isolation and elevated stress (especially in pressured roles) combine to boost absence rates linked to mental health, fatigue and seasonal affective disorder. The CIPD report notes mental ill-health as the leading cause of long-term absence and an increasing cause of short-term leave.

Caregiving and family-related absences add pressure

Beyond illness, many employees miss work because of school-age children, childcare breakdowns, or caring for older relatives. These pressures intensify during winter when infections spread in families. The knock-on effect? Managers suddenly short-staffed, teams under strain and cover arrangements pushed to breaking point.

Don’t react, forecast: using data to anticipate absence

Analyse historic absence data now

Your best defence is foresight. Pull your absence-management system and analyse:

• Which months in previous years saw peaks?

• Which departments were most affected?

• Which roles or locations are particularly vulnerable (front-line, shift work, high-travel)?

Segmenting by department, role or geography uncovers the hotspots that need pre-emptive action.

Integrate absence analytics into workforce planning

Link absence predictions to your scheduling, project planning or shift-rota decisions. If your forecast shows likely absence peaks in January to February, you might plan less workload, schedule cross-training, or bring in temporary cover.
If your absence data still lives in spreadsheets, it’s time to upgrade.

Strengthen employee wellbeing to prevent absence

Promote flu vaccination and early intervention

Make flu jabs accessible with on-site clinics or vouchers. Communicate the benefits clearly. Encourage employees to seek early treatment if they feel unwell rather than soldier on.

Tackle winter fatigue and mental health

Offer wellbeing check-ins, increase awareness of seasonal affective disorder, provide access to employee-assistance programmes (EAPs) and consider daylight exposure initiatives (such as light therapy options or encouraging outdoor breaks). These approaches help you not just react to illness but build resilience.

Support flexible and hybrid work during winter

Allowing remote or hybrid work can reduce contagion risk, reduce commuting stress in poor weather, and support colleagues who might have caring responsibilities or feel less able to commute when unwell.

Five-point winter wellbeing checklist:

1. Flu vaccine access & communication plan

2. Mental-health check-ins and manager training

3. Lighting/space review

4. Flexible/hybrid work policy

5. Absence reporting and early intervention process refresh

Refresh policies and communication before the cold hits

Clarify sickness-reporting processes

Ensure every employee knows who to contact, how to log absence and what the expectations are. A clear process reduces confusion and prevents unreported or loosely handled absences.

Train managers on supportive conversations

Front-line peoplemanagers need to be confident: spot early warning signs, have open return-to-work discussions, and engage early rather than wait until issues escalate. Effective conversations reduce repeat absence.

Communicate clearly and compassionately

Draft internal emails or intranet posts reminding teams of self-care, reporting procedures and the organisational absence strategy.

A clear policy isn’t just compliance—it builds trust and reduces presenteeism.

Get your absence management policy template direct from BrightBase to ensure HR compliance and clarity.

The role of absence management software in a resilient hr strategy

Our absence-management tool automates many of the pain points: it logs absence, triggers policy alerts (e.g., high-frequency absence), and integrates with wellbeing platforms (EAPs, mental-health apps).

Using software means you shift from reaction (“Oh no, three people off this week”) to strategy (“We forecast a spike in Week 4, we’ve bookmarked cover, flagged managers and communicated prevention tips”). Integrations with wellbeing apps help you link absence data with early intervention reach.

See how our absence management software can help your business stay productive this winter.

Turn winter absence into a strategic advantage

Winter absence doesn’t have to be a crisis; it can be an opportunity for HR to demonstrate strategic value to the business. By planning early, using predictive data, strengthening wellbeing and deploying the right tools, you position your workforce for success even in the lean winter months.

Start the conversation today: embed your winter absence plan into your 2025/26 workforce strategy. With the right approach, you’ll reduce disruption, maintain team resilience and protect productivity.