Yes, it can manifest even before the baby reaches a year old. Some allergies come out after the baby turns 1. We were advised to continue breastfeeding since I have history of allergy to prolong or totally avoid the symptoms during the early years.
According to this, even babies below one year of age can have allergies. Some babies are even as young as 6 months! You may want to read this for more info http://www.parents.com/baby/health/allergy/all-about-baby-allergies/
According to our Pedia, allergies can manifest on babies as early as 1 year old. If your allergic to weather transition, your baby might inherited that. Visit your pedia asap.