Select min_vals.*,
max_value,
max_value_hour
From (
   Select top 1 with ties 
   area_name,place_name, object_name, class 
   value as min_value, 
   hour as min_value_hour
     From table 
   Where year = @year_to_calc and 
   month = @month_to_calc and
   day = @day_to_calc
   Order by Row_Number() over (Partition by area_name,place_name, object_name, class Order by Value
) min_vals
join 
(
   Select top 1 with ties 
   area_name,place_name, object_name, class 
   value as max_value, 
   hour as max_value_hour
     From table 
   Where year = @year_to_calc and 
   month = @month_to_calc and
   day = @day_to_calc
   Order by Row_Number() over (Partition by area_name,place_name, object_name, class Order by Value desc
) max_vals 
on min_vals.area_name = max_vals.area_name
and min_vals.place_name = max_vals.place_name
and min_vals.object_name = max_vals.object_name
and min_vals.class  = max_vals.class