Womens bike gloves not only provide warmth in cold weather but help deal with warmth in hot conditions.
Lets deal with the cold first. Long fingered gloves insulate your hands providing warmth. Depending on the severity of the conditions you can find varying degrees of warmth to match. Remember you still need to maintain good control on your handlebars which means being able to grip them correctly. This is when having the correct glove size is important and not too much bulk.If your long fingered winter gloves also need to control sweat look for mesh inserts and wicking fabrics.
In the heat, or if you tend to sweat quite a lot while riding, gloves should keep your hands dry. Dry hands are safe hands that can maintain a good grip and control on your handlebar. Gloves should be made from wicking fabric that absorbs and pulls mositure away from the skin. During the warmer riding months fingerless gloves provide all the benefits of protection and comfort but allow for some airflow around the fingers.