Temperature, sunshine, humidity, and barometric pressure influence how we feel physically and how well we perform mentally. Despite skeptics, many scientists believe weather is an important factor in mood and mental functioning. It's difficult, however, to determine the full impact of weather since people in industrialized countries such as the U.S. spend-on average-93 percent of their time indoors.

Sunshine and warm weather both boosts mood to a point. The optimal temperature for most people is 72. On the other hand, extreme heat and cold tend to depress mood. 

Sunlight exposure may also affect mental functioning. As you might expect, lower levels of sunlight are associated with impaired mental performance. Sunlight affects serotonin, a neurotransmitter associated with mood, and melatonin, a sleep-related hormone that increases during dark and may cause symptoms of depression.

If you're one of the millions who suffer from Seasonal Affective Disorder (SAD), you know that environment and lifestyle profoundly affect mood. SAD is a type of depression that typically strikes in the fall and winter. Scientists believe shifts in our biological internal clocks, partly in response to changes in sunlight patterns, triggers SAD.

Using the Weather to Boost Your Mood

Take a stroll. Walk outdoors for at least 30 minutes when the sun is shining, even if it's not the optimal temperature. In addition to improving your mood, you'll increase your body's supply of vitamin D and the exercise will help reduce symptoms of depression.

Explore artificial light exposure. More than 80 percent of SAD sufferers improve when they use light therapy. These lights are typically 10 times the intensity of normal light bulbs. Exposure to artificial light also increases alertness. Scientists suspect light therapy corrects problems in brain chemistry caused by light deprivation. Begin light therapy when your symptoms start in the fall. Do not use tanning beds, however; they significantly increase your risk for skin cancer.

Take a hike. Ecotherapy, a new breed of treatment for depression and other mood disorders, taps into the power of ecology to provide therapeutic benefit and studies do show that ecotherapy provides substantial health benefits. In one study, depression decreased in 71 percent of the participants following a walk in a green park, while feelings of depression increased for 22 percent of those who walked at an indoor shopping center.

Finally, if possible, schedule a trip to warmer, sunnier climes for a therapeutic, mid-winter mood boost.

Sources

Kent, Shia T., McClure, Leslie A., Crosson, William L., Arnett, Donna K., Wadley, Virginia G., and Sathiakumar, Nalini. "Effect of sunlight exposure on cognitive function among depressed and non-depressed participants: a REGARDS cross-sectional study." Environmental Health 8:34 (2009):  doi 10.1186/1476-069X-8-34. Web.

Paddock, Catharine. "Green Walking Beats The Blues, New Study Recommends Ecotherapy For Depression." Medical News Today. Web. 14 May 2007.

Serwach, Joseph. "Warm weather boosts mood, broadens the mind." The University Record Online. University of Michigan. Web. 24 October 2003. Web.

McGroarty, Kent. "Weather Affecting Your Mood?" Edge. Web. 14 March 2009.

Denissen, Jaap J. A., Butalid, Ligaya,  Penke, Lars and van Aken, Marcel A. G. " The Effects of Weather on Daily Mood: A Multilevel Approach." Emotion Vol. 8, No. 5, (2008): 662-667. Web.

Dear Doctor Column, "Seasonal Affective Disorder." UAB Health System. Web. 24 March 2003.