Seasons influence far more than our wardrobes or social plans — they can deeply affect our mental health. While most people have heard of Seasonal Affective Disorder (SAD), the truth is that changing light, temperature, and biological rhythms can impact a wide range of mental health conditions — from depression and anxiety to schizophrenia and bipolar disorder.
☀️ The Science Behind Seasonal Shifts in Mood
Light Exposure
Daylight plays a key role in regulating serotonin (the “feel-good” hormone) and melatonin (which helps control sleep).
- Winter: Shorter daylight hours can reduce serotonin and disrupt circadian rhythms, leading to fatigue, sadness, and low motivation — all classic symptoms of SAD.
- Summer: Too much sunlight can interfere with sleep, heighten irritability, and even trigger anxiety in some people.
🧠 Fact: Around 1 in 15 people in the UK experience Seasonal Affective Disorder, with symptoms typically appearing between September and April.
(Source: NHS, 2024)
Temperature and Weather
Extreme heat can take a toll on both the body and mind:
- High temperatures increase irritability, aggression, and anxiety.
- Hot nights can disrupt sleep, which worsens mood and cognitive function.
- Cold, wet, or stormy weather can make people withdraw socially, deepening isolation.
💧 Did you know? Studies show that violent crime rates and aggressive behaviour tend to rise during heatwaves — a phenomenon linked to overstimulation of the nervous system due to heat stress.
Disrupted Biological Rhythms
Our bodies have internal “clocks” — the circadian rhythms — that control sleep, hormones, and energy. Rapid changes in daylight and temperature can throw this rhythm off balance, leading to:
- Difficulty sleeping
- Increased fatigue
- Emotional instability
This disruption particularly affects people with mood disorders or schizophrenia, whose biological rhythms are already sensitive to change.
🌻 Season-by-Season Breakdown
Winter: The Classic SAD Season
- Common symptoms: Fatigue, overeating, oversleeping, and low mood.
- Cause: Reduced daylight and less outdoor activity.
- Tip: Use light therapy lamps, maintain a routine, and take walks during daylight hours.
Summer: Heat, Anxiety & Irritability
- Common symptoms: Restlessness, poor sleep, and anxiety.
- Cause: Heat disrupting sleep, excessive daylight, and dehydration.
- Tip: Stay hydrated, use fans or cooling packs, and reduce caffeine or alcohol intake.
Spring: Renewal or Risk?
- Common symptoms: Sudden mood shifts or energy surges in people with depression or bipolar disorder.
- Fact: Studies show that suicide rates peak in late spring — possibly linked to hormonal and social activity changes.
- Tip: Stay connected, check in with others, and seek professional support if your mood suddenly changes.
🌍 Climate Change & Mental Health
Rising global temperatures and extreme weather events are contributing to a new type of mental strain: climate anxiety.
People are increasingly experiencing stress and grief linked to environmental changes, especially younger generations who feel uncertain about the future.
🧘♀️ What You Can Do
✅ Seek Professional Help
Therapies like Cognitive Behavioural Therapy (CBT) and light therapy can be effective for SAD and seasonal mood issues.
✅ Monitor Your Mood
Keep a mood diary to track how changes in weather or daylight affect your mental health.
✅ Adapt Your Environment
- In winter, increase light exposure and stay active.
- In summer, limit overheating, manage hydration, and prioritise rest.
🌈 Final Thoughts
Our mental health is deeply intertwined with nature’s rhythms. Recognising how seasons affect your mood isn’t a sign of weakness — it’s a sign of awareness. Whether it’s the fatigue of winter or the restlessness of summer, small, mindful adjustments can make a big difference in maintaining balance throughout the year.

