"...Nicer weather was associated with better mood, memory and a broader mindset, but only among participants who’d spent more than 30 minutes outside".In a second experiment conducted on various days in Spring and early Summer, 121 participants completed tests of their mood and short-term memory before and after relaxing for 30 minutes. Half the participants were asked to relax outdoors, the others indoors. Consistent with the first experiment, the researchers found that when the weather was good, participants’ mood and memory tended to have improved after they’d relaxed outdoors, but not if they’d relaxed indoors.
A final study was conducted to take into account other geographical locations and times of year. As before, more pleasant weather was found to enhance the mood of people who’d been outside for long enough, but it only had this benefit in Spring – probably because in Summer it can often get too hot for comfort, the authors said.
Keller, M.C., Fredrickson, B.L., Ybarra, O., Cote, S., Johnson, K., Mikels, J., Conway, A. & Wager, T. (2005). A warm heart and a clear head. The contingent effects of weather on mood and cognition. Psychological Science, 16, 724-731.