With the exception of São Luís , the main draw of the Northeast coast  is its beaches. So how you plan your time really depends on whether you’re restless and want to beach hop, or would rather just choose one or two idyllic getaways where you can veg out.
Rio Grande do Norte  is a small state. By basing yourself in Natal , you can very easily spend 5–7 days exploring the coastline north  and south  of the city, while stopping for a couple of days at Praia da Pipa .
Sprawling Ceará  deserves a little more time. If you avoid the tourist traps, Fortaleza , while not beautiful, is an interesting and vibrant city that warrants a day or two, and more if you want to do some day trips. You’ll be disappointed if you don’t stay over in Canoa Quebrada , and plan at least 4–5 days for Jericoacoara  (it takes close to a day just to get there).
Some people end up staying in “Jeri” for weeks. As for São Luís, three days is the minimum you’d want to stay. Having come so far, it would be a crime not to add another three days to explore the dunes and lagoons of the Lençóis Maranhenses .
Traveling between Natal and Fortaleza is easy, and all of Ceará’s beaches are quite accessible by bus and car (some of Rio Grande do Norte’s are more difficult to access without wheels). São Luís is quite isolated. Bus service from other cities takes forever and plane fare is fairly steep. Adventurous souls with time on their hands (a week or two) can travel by Jeep (and, in parts, by dune buggy) up the entire coastline, from Natal  to São Luís .
Due to its proximity to the Equator, you’ll find the Northeast coast hot year-round. Rio Grande do Norte  and Ceará  are notoriously sunny. Even during the so-called “rainy season,” which generally occurs March–May—you’re treated to quick downpours more than days of drizzle. Under the sway of the Amazon ’s climate, Maranhão  is considerably wetter, particularly between January and May.
If you want the beaches to yourself, avoid peak seasons of January, February, and July when both Rio Grande do Norte and Ceará are mobbed by Brazilian and international tourists.