I love the great outdoors. Nothing like fresh air in the lungs and a little natural vitamin D from the sun.
I venture outdoors in all seasons, even in the winter. "It's too cold outside" is an excuse that most people use. However, if you dress appropriately, you can still enjoy an open-air workout.
Dressing in layers is best. Next to your skin wear a synthetic fibre that wicks away moisture (avoid cotton). Your second layer should be fleece or wool for insulation. For your outer layer, wear a light coat made of nylon, or something similar, that will guard against the wind & the rain/snow. To complete your outfit, wear warmer socks, shoes with a good grip, light gloves and a hat.
Research suggests that an open-air workout can be more psychologically restorative than an indoor workout. Even a quick walk around the block can help with seasonal affective disorder & depression.
Add variety to your workout, avoid the flu & cold viruses that people bring to the gym and get outdoors for a change. It will put a smile on your face & color on your cheeks.