Strong floral perfumes, as well as anything sweet such as vanilla scents, tend to take on a stronger, almost overbearing scent once the chemicals in the perfume are mixed with heat. Ironically enough, even though your perfume will smell stronger, (in a bad way), it will not last long once introduced to heat. You will find that you are needing to reapply your fragrance throughout the day.
Perfumes you want to peruse during the summer months are: light florals , "oceanic" perfumes, (Island by Michael Kors, Cool water by DavidOff) and citrus blends.
Ralph by Ralph Lauren...
Ralph by Ralph Lauren...
...used to be one of my favorite summer perfumes, it has a very distinct, yet refreshing scent.
Having said that, there are many perfumes that have a summer limited edition version, so you might want to research your favorite perfume and see if there is a special version for summer months.
Flowerbomb, which happens to be a favorite of mine, has a summer edition that is lighter on the floral notes. Many perfumes have summer editions, so keep that in mind.