By Dr. Mercola
Weather can be sunny, stormy, dreary or unpredictable but then so, too, can your mood. The way you feel on any given day may actually be intricately tied to the weather forecast in ways science is only beginning to understand.
Many people are now aware that spending time outdoors on a sunny day, and allowing the sun to shine on your bare skin, is necessary for your body to produce vitamin D, which also plays a role in serotonin production.
Serotonin, the brain hormone associated with mood elevation, rises with exposure to bright light and falls with decreased sun exposure. This is one reason why bright-light therapy is so effective for treating people with seasonal affective disorder (SAD), which is sometimes referred to as ‘winter depression.’
This is only the tip of the iceberg, however. A sunny day can make you feel inexplicably happy, but only if you can frolic outdoors. People who are stuck indoors on a sunny day may feel their mood plummet, and the weather also has significant (and often subconscious) effects on behavior and more.
Pleasant Weather Improves Mood and Broadens Cognition
The association between weather and psychological changes has led to some inconsistent results. Research published in the journal Psychological Science found this may be due to two important factors: the season and how much time is spent outside.
Pleasant weather was associated with higher mood, better memory and ‘broadened’ cognitive style during the spring as time spent outside increased. The same could not be said for mood and weather during other times of the year, and the hot summer months were associated with lower mood.
The researchers reasoned that pleasant springtime weather has such a positive effect because people have been deprived of pleasant weather during the winter.1 Researcher Matthew Keller summed it up quite simply by saying, “If you wish to reap the psychological benefits of good springtime weather, go outside.”2
How the Weather May Control Your Behavior
When the sun comes out, you may alter your behavior without even realizing it. Studies suggest, for instance, that on sunny days people help each other more and leave more generous tips when eating at restaurants.3
Research published in The Journal of Finance even found sunshine is significantly associated with stock returns (while rain and snow are not).4 If you’re looking to find a date, you may fare better when the weather’s sunny as well.
One French study found women were more receptive to giving their phone number to an attractive stranger on sunny days compared to cloudy days, providing their number 22 percent of the time and 14 percent of the time, respectively.5
Another study conducted by the same researcher, French psychologist Nicolas Guéguen, also found drivers were more likely to pick up hitchhikers on sunny days than they were on cloudy days. “Perhaps the positive mood induced by the sunshine promotes helping behaviors,” he and a colleague concluded.6
On the other hand, separate research revealed that the further the temperature rises or falls from an ideal 68 degrees F, the lower helping rates become.7
Weather Influences Your Mental Health (and Maybe Your Chances of College Admission)
People have been found to recall up to seven times more objects when quizzed on cloudy days as opposed to sunny ones.8 “Shoppers in a negative mood showed better memory and higher discrimination ability,” the researchers noted.
Still other research analyzed 682 actual university admission decisions. It turned out that applicants' academic attributes are weighted more heavily on cloudier days while non-academic attributes were given more weight on sunnier days.9 According to the study:
“The documented effects are of both statistical and practical significance: changes in cloud cover can increase a candidate's predicted probability of admission by an average of up to 11.9 percent.”
Crime Rates Rise Along With the Temperature
Sunny weather isn’t always a good thing, however, particularly when it means temperatures are high. Crime rates increase during the summer months, according to the U.S. Department of Justice (DOJ).
A DOJ study revealed rates of serious violent crimes, household larceny and household property victimization are significantly higher in summer months.10 There are a couple of reasons why this may be.
Hot, sticky weather may make people feel irritable, causing them to act out with increased aggression and hostility. Summer weather also attracts people outdoors, which means there are more social interactions and more opportunities for arguments and crimes to ensue.
The exception is when it starts to get really hot (90 degrees F and over); then even criminals tend to stay inside to cool off. The Epoch Times continued:11
“Aspects of weather beyond heat and sunshine have also been shown to affect mood. Humidity tends to make people more tired and irritable.
Barometric pressure fluctuations can alter moods and trigger headaches, some studies finding a link between low pressure and suicide. On rainy days, people report lower satisfaction with their lives.”
Fresh Air and Sunshine May Help Relieve Depression
“I know only too well how a sunny day can mock you and taunt you and make you feel even worse than you already do. You close the blinds, pull the blanket back over your head and wish that you had the energy to go outside.
The truth is, however, that going outside and getting a little bit of sun and fresh air can go a long way to relieving depression symptoms, even if it’s just for a little while. I didn’t stay out for long, only about 20 minutes, cleaning up here and there.
I could almost feel the vitamin D, sometimes called the sunshine vitamin, seeping into my skin. Okay, I know, that was a little over the top. But still, those twenty short minutes in the sun and fresh air revived me. For the first time in a long time, I felt energized.”
It may sound like a stretch, but giving your body a dose of needed vitamin D may have a significant effect on your mood and even more so if it’s done regularly to keep your levels within the optimal range. People suffering from anxiety and depression are more likely to have vitamin D deficiency.13
Further, in one previous study seniors with the lowest levels of vitamin D were found to be 11 times more prone to be depressed than those who had normal levels. A double-blind randomized trial published in 2008 also concluded:14
"It appears to be a relation between serum levels of 25(OH)D and symptoms of depression. Supplementation with high doses of vitamin D seems to ameliorate these symptoms indicating a possible causal relationship."
Spending Time in Green Spaces Also Enhances Your Mood
Spending time in green spaces has psychological and physical benefits. Simply taking a walk in a natural area has been shown to decrease the pattern of negative thinking known as rumination, which is linked to an increased risk of depression.15 Those researchers noted:
“This study reveals a pathway by which nature experience may improve mental well-being and suggests that accessible natural areas within urban contexts may be a critical resource for mental health in our rapidly urbanizing world.”
Indeed, more than 80 percent of Americans live in urban areas,16 which can limit access to green spaces and potentially worsen public health. In addition to improving well-being, those living in a greener environment report fewer health complaints and better mental health.17
All types of green space — city parks, agricultural areas, forest, etc. — were equally beneficial. Cognitive function may also improve. In a study of 2,600 children between the ages of 7 and 10, those with greater exposure to green spaces, particularly while at school, had improved working memory and decreased inattentiveness.18
A 2014 study similarly found that children attending schools with greater amounts of vegetation scored higher on academic tests in both English and math.19
A 50-Minute Nature Walk Improves Mood and Memory
Not to mention, older adults who spend more time outdoors have less pain, sleep better and have less functional decline in their ability to carry out their daily activities.20 Research published in 2015 also found immense benefits from taking a 50-minute walk in a natural area compared to a similar walk in an urban area. The researchers noted:21
“ ... the nature walk resulted in affective benefits (decreased anxiety, rumination, and negative affect, and preservation of positive affect) as well as cognitive benefits (increased working memory performance).”
These studies didn’t look into the weather per se, just the act of getting outside, so it may be that spending time outdoors in nature is beneficial regardless of the weather.
Even Photos of Green Spaces may Lessen Stress
Urbanization is associated with an increase in stress-related diseases and mental disorders for those living in urban environments. A recent study published in The International Journal of Environmental Research and Public Health highlighted the need for residents of urban environments to find relief from urban stressors, preferably by having access to outdoor open spaces. Researchers explained:22
“There is increasing scientific evidence that particularly open spaces with natural or vegetated elements, e.g., green spaces, provide opportunities for restoration.
Numerous … studies have shown that contact with real or simulated green settings as opposed to built settings has positive effects on mood, self-esteem and self-reported feelings of stress and depression, and can help to recover from stress and attention fatigue.”
The study focused on the sympathetic and parasympathetic nervous systems, which handle stress either by triggering the ‘fight-or-flight response’ or by enhancing physiological calm, respectively.23 Students wore sensors to track their heart rates and other functions and then viewed photos of green or urban spaces.
The photos were shown both before and after the students conducted a serious of difficult math problems designed to raise stress levels. When photos of green spaces were seen after the math test, the parasympathetic nervous system was activated and lowered heart rates. The researchers concluded:24
“This study indicates that five minutes of viewing urban green space can support recovery from stress as shown in enhanced parasympathetic activity. These findings strengthen and deepen the growing evidence-base for health benefits of green space in the living environment. In particular, the present findings point to the importance of visual access to green space in providing readily available micro-restorative opportunities.”
Get Outdoors Often When the Weather Is Pleasant
The take-home message here is simple: when it’s nice outside, get outdoors and soak it in as often as you can. Parks, nature preserves and backyards can all provide children and adults with much-needed access to green space as well, so for the best results try to take in nice weather while surrounded by nature.
If you live in a locale with frequent poor weather and you believe it’s negatively affecting your mood, you may wish to consider moving to a region with a better climate.