Its advisable to invest in SPF of at least 30 because you’ll be needing it, twill be your best friend, lighter makeup is advisable also.
You can ditch your foundations for something lighter like bb creams, because the heat, sweat and cracks that will accompany heavy make-ups at this time.
Harmattan can cause your skin to be dry and cracked, it will be in your best interest to add coconut oil, olive oil, shea or baby lotion to your body creams.
You also need to stay hydrated by taking lots of water or fruits that contain lots of water eg: cucumbers & watermelons
Exfoliate & keeper your lip balm handy to combat chapped lips.