DECLARE @Year int = 2015 
SELECT A.Address,@Year AS [Year],M.[MONTH]
,case WHEN FE.DIFF <= PE.DIFF  THEN FE.Event
      WHEN PE.DIFF IS NOT NULL THEN PE.Event
      ELSE NULL END AS Event 
FROM
(SELECT Address FROM FactEvents UNION SELECT Address FROM PlanEvents) A
CROSS JOIN 
(SELECT 1 AS [MONTH] 
UNION SELECT 2 
UNION SELECT 3 
UNION SELECT 4
UNION SELECT 5
UNION SELECT 6
UNION SELECT 7
UNION SELECT 8
UNION SELECT 9
UNION SELECT 10
UNION SELECT 11
UNION SELECT 12
     ) M
OUTER APPLY(SELECT TOP 1 ABS(Month-M.Month) AS DIFF,[EVENT] FROM FactEvents WHERE Address = A.Address AND Year = @Year ORDER BY ABS(Month-M.Month)) FE    
OUTER APPLY(SELECT TOP 1 ABS(Month-M.Month) AS DIFF,[EVENT] FROM PlanEvents WHERE Address = A.Address AND Year = @Year ORDER BY ABS(Month-M.Month)) PE    

SELECT A.Address,Y.[Year] AS [Year],M.[MONTH]
,case WHEN FE.DIFF <= PE.DIFF  THEN FE.Event
      WHEN PE.DIFF IS NOT NULL THEN PE.Event
      ELSE NULL END AS Event 
FROM
(SELECT Address FROM FactEvents UNION SELECT Address FROM PlanEvents) A
CROSS JOIN (SELECT [Year] FROM FactEvents UNION SELECT [Year] FROM PlanEvents) Y
CROSS JOIN 
(SELECT 1 AS [MONTH] 
UNION SELECT 2 
UNION SELECT 3 
UNION SELECT 4
UNION SELECT 5
UNION SELECT 6
UNION SELECT 7
UNION SELECT 8
UNION SELECT 9
UNION SELECT 10
UNION SELECT 11
UNION SELECT 12
     ) M
OUTER APPLY(SELECT TOP 1 ABS(Month-M.Month) AS DIFF,[EVENT] FROM FactEvents WHERE Address = A.Address AND Year = Y.[Year] ORDER BY ABS(Month-M.Month)) FE    
OUTER APPLY(SELECT TOP 1 ABS(Month-M.Month) AS DIFF,[EVENT] FROM PlanEvents WHERE Address = A.Address AND Year = Y.[Year] ORDER BY ABS(Month-M.Month)) PE    
ORDER BY Y.[Year],M.Month

declare  @Calendar table(yy int, mm int);
insert into @Calendar values
(2015,	1),
(2015,	2),
(2015,	3),
(2015,	4),
(2015,	5),
(2015,	6),
(2015,	7);

declare @FactEvents table (Address nvarchar(100), yy int, mm int, Event nvarchar(100));
insert into @FactEvents values
(N'Ул. Ленина 1',	2015,	1,	N'Событие 1'),
(N'Ул. Ленина 1',	2015,	7,	N'Событие 2');

with all_addr as
(
select distinct Address
from @FactEvents
)

select c.yy, c.mm, a.Address, f.Event
from @Calendar c cross join all_addr a
     left join @FactEvents f on c.yy = f.yy and c.mm = f.mm and a.Address = f.Address;

(Календарь CROSS JOIN СписокАдресов) LEFT JOIN Событие 

(Календарь CROSS JOIN СписокАдресов) OUTER APPLY (SELECT TOP 1 * FROM Событие )