Select the right perm rods for the style you want. In general, hair wraps around bigger rods fewer times, for a loose curl. Hair wraps around smaller rods many times, for a tighter curl. Also select the right permanent lotion for the hair. An average strength lotion works on normal hair, a weak lotion on damaged or dyed hair and a strong lotion on perm-resistant hair.
Wash the hair before you perm, because a perm takes better in clean hair. Additionally, perm solution should be applied to wet hair as a rule, because lotion sinks into wet hair more evenly than dry hair. Applying perm lotion to wet hair in humid weather means that humidity has no effect on the perm's hold.
Comb out the hair after washing.
Select a thin section of hair that's almost as wide as your perm roller. Put the roller on the hair, then roll it up the hair's length. Secure the roller using its clip or pin once you've rolled the hair up to the roots.
Put all the hair in rollers the same way. The hair should be wet or damp. If the hair starts feeling dry, spritz it with a water bottle to maintain moisture.
Put latex gloves on to protect your hands, then coat the hair with the permanent lotion. Dab the lotion onto all visible hair. The lotion spreads through wet or damp hair for even processing.
Set a timer for the recommended time, which will be on the permanent lotion bottle.
Rinse the hair under warm water when time is up or curls have set.
Apply a neutralizing rinse, which stops the action of any chemicals trapped in the hair. Coat hair with the rinse, then let it seep in for the recommended processing time on the bottle.
Rinse out the neutralizer when time is up.
Remove the perm rods. Blot the hair dry with a towel.
While humidity doesn't affect the perm process, temperature may. If it's cold inside the hair salon, the perm lotion needs more time to process. If it's hot in the salon -- more likely in humid weather -- the lotion might process more quickly. Check on the lotion during the process by unrolling a curl. If the curl holds an S-shape, you can rinse out the permanent lotion.