While we may not work as hard when it's sunny, there are plenty of benefits. Natural sunlight hits the skin and provides people with Vitamin D, which protects against inflammation and lowers blood pressure. Vitamin D also improves brain function, which may help us refocus when we're daydreaming.
Studies show sunlight may bring a reduced risk of breast and prostate cancers, also because of Vitamin D.
One report says to target at least 10 minutes of non-sunscreened exposure to the sun every day. (Any more than that might lead to sunburn.)