Most items are not heat sensitive and can ship anytime. 

See Also: 1. Heat Sensitive 2. Heat Maps 3. Ship Time 4. Cool shipping

Heat Sensitive items are listed with temperatures above their descriptions.

No 70°-90°F heat sensitive items to  southern states  during June, July, and August.  
Southern States: Florida, Louisiana, Texas, New Mexico, Arizona, Nevada and California. 

Typically it's above  80°F / 26°C during June, July and August in the US.
Southern States are also typically above 80°F during May and September.

Heat Sensitive's that need cool ship  over 80° F  (26°C) :

All Chocolates, M&M's, rainbow mix, and giant mints. 
        (When over 70°F (21°C) No Lindt Truffles)
Confections, yogurt & carob confections, baking drops and coatings, smooth and melty mints, sweet and salty mix,  Neapolitan coconuts, coconut bonbons and haystacks.  Unwrapped Cases: Lemon drops, horehound, and cinnamon balls.

 Heat sensitives that need cool ship  over 90°F  (32°C) :

Medjool dates, date rolls, cherry sours, cinnamon imperials, Reese's pieces, Cases of sugar free hard candy , candy corn,  jolly ranchers, jelly beans but NOT Jelly Belly jelly beans, and peach gummy rings. Unwrapped Packaged: Lemon drops, horehound, and cinnamon balls.