Does time outside help your mood? What the research actually says

Probably, a bit, for many people, and the research is more careful than the headlines about it. Here is what the studies actually found, in their own words, with the caveats they put on their own findings.

Written by the Perfect Day team. Every source below was opened and quoted on 16 September 2026; nothing here is medical advice, and the last section says what these studies cannot tell you.

Updated 16 September 2026.

The short version

Large surveys find that people who spend time in nature more often report better health and wellbeing. One well-known study puts a rough figure on “more often”: around two hours a week. Experiments find that pleasant weather lifts mood and sharpens thinking — but mainly in spring, and only for people who actually go outside in it. Programmes that prescribe time in nature show promising results, with the evidence still young. All of it is association and early trials, not proof of cause, and every author below says so.

Two hours a week: White and colleagues, 2019

A survey of nearly twenty thousand people in England, published in Scientific Reports. Its title is its finding: “Spending at least 120 minutes a week in nature is associated with good health and wellbeing”. In the abstract's words: Compared to no nature contact last week, the likelihood of reporting good health or high well-being became significantly greater with contact ≥120 mins. The word the authors chose is associated: the people who reported the time also reported the wellbeing. The study does not show that the time caused it, and the authors do not claim so. It also found that how the two hours were made up — one long visit or several short ones — did not seem to matter.

Weather, mood and thinking: Keller and colleagues, 2005

A set of studies in Psychological Science, “A warm heart and a clear head: the contingent effects of weather on mood and cognition”, found that pleasant weather (higher temperature or barometric pressure) was related to higher mood, better memory, and ‘broadened’ cognitive style during the spring as time spent outside increased. Two things in that sentence matter for a day out. First, as time spent outside increased: the pleasant weather did not help the people who stayed in. Second, during the spring. The authors go on: The same relationships between mood and weather were not observed during other times of year, and indeed hotter weather was associated with lower mood in the summer. A good day is not the same as a hot one, which is a large part of why Perfect Day judges dew point and not just the thermometer.

Nature on prescription: Nguyen and colleagues, 2023

A systematic review in The Lancet Planetary Health, “Effect of nature prescriptions on cardiometabolic and mental health, and physical activity”, pooled trials in which people were formally prescribed time in nature. It found that nature prescription programmes resulted in a greater reduction in systolic blood pressure than comparison conditions, and that nature prescriptions also had a moderate to large effect on depression scores and anxiety scores. The authors' own caveat sits next to that: Most studies have a moderate to high risk of bias. Promising is the right word; settled is not.

What people say themselves

The UK's Mental Health Foundation reports from its own research that throughout the pandemic, nearly half (45%) of people in the UK told us that visiting green spaces, such as parks, helped them to cope (Mental Health Foundation). That is people describing their own experience, which is worth hearing and is not the same kind of evidence as a trial.

What none of this tells you

These studies cannot tell you that time outside will make you feel better, or by how much, or instead of anything else. Surveys find associations, and people who feel well may simply go out more. Experiments find effects that depend on season and on actually being outside. Reviews of prescription programmes report early results from trials the reviewers themselves rate as often at risk of bias. Nothing here treats, prevents or cures anything, and a good day outside is not a substitute for care from someone qualified to give it. If you are struggling, please talk to a doctor or a helpline.

What the research does support, modestly, is the thing most people already believe: that time in a pleasant place outdoors is linked to feeling better, that the pleasant part matters, and that the hardest step is going. We built Perfect Day for the last of those. It does not promise a feeling. It watches for the good day, and tells you when it is coming, so that the going is easier.

Related

• How to get outside more when you don't feel like it
• A day off, outside: ideas sorted by the weather