Filter Date of birth for same age and particular month

create table ##age (id int,dob datetime)
insert into ##age values(1,'1990-02-25 09:18:58.740')
insert into ##age values(2,'1990-07-01 09:18:58.740')
insert into ##age values(3,'1998-05-25 09:18:58.740')
insert into ##age values(4,'1990-08-25 09:18:58.740')

create table #temp (id int,dob datetime,age int,month int)

insert into #temp (id,dob,age,month)
select id,dob,DATEDIFF(yy, dob, GETDATE()) - CASE WHEN
(MONTH(dob) > MONTH(GETDATE())) OR (MONTH(dob) = MONTH(GETDATE()) AND DAY(dob) > DAY(GETDATE())) THEN 1 ELSE 0 END as age,month(dob) as [month] from ##age

select * from #temp
select * from #temp where age =26 and [month] in (1,2,3,4,5,6,7,8)