Federal Reserve Seasonal Factors for Domestic Auto and Truck Production

Release Date: March 16, 2018

Seasonal factors for auto and truck production were revised from January 2006 through June 2019 on March 16, 2018. The revised factors for September 2017 through February 2018 were used in the G.17 release issued on March 16, 2018, and the revised factors for earlier months will be incorporated into the production estimates at the time of the annual revision on March 23, 2018. The revised seasonal factors are based on production data through January 2018. The seasonal factors will be revised again in March 2019.

Monthly figures for motor vehicle assemblies in millions of units at an annual rate are published in Table 3 of the G.17 release. The formula for seasonally adjusted annual rates (SAAR) of auto and truck production (in millions of units) for each month is

       SAAR = ((NSA data in units/1,000,000) * 12)/(SF * .01).

The not seasonally adjusted (NSA) data are obtained from Ward's Communications, and the seasonal factors (SF), which contain adjustments for holiday and length-of-month effects as well as normal seasonal variation, are shown in the table below under "Regular Seasonal Factors."

The table below also shows a set of seasonal factors on a weekday average basis (SFW) in the columns under "Weekday-basis Seasonal Factors"; the number of production days in a month, or weekdays, is shown separately. Using this information, the formula for seasonally adjusted annual rates of auto and truck production (in millions of units) for each month is

       SAAR = ((NSA data in units/1,000,000) * 260)/(weekdays * SFW * .01).

Multiplying by 260, the average number of weekdays in a year, converts the weekday average production to an annual production rate. This formula reduces to

       SAAR = (NSA data in units * .026) / (weekdays * SFW).

A comma-delimited text file containing these seasonal factors is available for download here.

    

Monthly Seasonal Factors for Domestic Auto and Truck Production
  Regular Seasonal Factors Weekday-basis Seasonal Factors
 
Autos
Total
Trucks
Light
Trucks
 
Autos
Total
Trucks
Light
Trucks
 
Weekdays
Jan-1996  98.90  99.23  99.39  93.17  93.48  93.63 23
Feb-1996 104.64 105.93 106.22 107.96 109.29 109.59 21
Mar-1996 108.03 109.04 109.30 111.46 112.50 112.77 21
Apr-1996 105.93 106.96 106.85 104.32 105.34 105.24 22
May-1996 113.46 113.06 113.36 106.89 106.51 106.79 23
Jun-1996 103.34 102.29 102.25 111.96 110.82 110.77 20
Jul-1996  63.77  60.55  59.31  60.07  57.04  55.87 23
Aug-1996 100.73 102.41 102.30  99.20 100.86 100.75 22
Sep-1996 100.49 100.87 101.06 103.68 104.08 104.27 21
Oct-1996 118.79 119.65 119.80 111.90 112.72 112.86 23
Nov-1996  98.09  97.55  97.82 101.20 100.64 100.92 21
Dec-1996  79.00  78.52  78.46  77.80  77.33  77.27 22
Jan-1997  98.79  99.08  99.27  93.07  93.34  93.51 23
Feb-1997  99.65 101.12 101.40 107.96 109.54 109.85 20
Mar-1997  97.86  98.66  98.91 100.97 101.80 102.05 21
Apr-1997 116.38 117.22 117.08 114.62 115.44 115.31 22
May-1997 111.28 110.92 111.17 109.60 109.24 109.49 22
Jun-1997 103.03 101.86 101.75 106.30 105.09 104.98 21
Jul-1997  69.50  65.81  64.39  65.47  61.99  60.66 23
Aug-1997  97.62  98.57  98.50 100.72 101.69 101.63 21
Sep-1997 106.09 106.16 106.37 104.48 104.55 104.75 22
Oct-1997 118.16 119.23 119.35 111.31 112.31 112.43 23
Nov-1997  93.20  93.05  93.30 100.96 100.80 101.08 20
Dec-1997  88.97  89.30  89.30  83.81  84.12  84.13 23
Jan-1998  89.59  89.49  89.69  88.23  88.14  88.33 22
Feb-1998  99.59 101.05 101.34 107.88 109.47 109.79 20
Mar-1998 113.53 114.17 114.45 111.81 112.44 112.72 22
Apr-1998 105.47 106.30 106.18 103.87 104.69 104.57 22
May-1998 105.36 105.18 105.37 108.71 108.52 108.72 21
Jun-1998 102.82 101.52 101.35 101.27  99.99  99.82 22
Jul-1998  72.63  68.79  67.28  68.42  64.80  63.38 23
Aug-1998  98.60  99.12  99.09 101.73 102.26 102.23 21
Sep-1998 106.68 106.49 106.70 105.06 104.87 105.09 22
Oct-1998 112.46 113.44 113.54 110.76 111.72 111.82 22
Nov-1998  93.76  93.51  93.78  96.74  96.48  96.75 21
Dec-1998  88.44  89.50  89.53  83.32  84.31  84.34 23
Jan-1999  89.54  89.41  89.62  92.38  92.25  92.47 21
Feb-1999  99.58 100.99 101.29 107.88 109.41 109.73 20
Mar-1999 118.62 119.28 119.58 111.74 112.36 112.65 23
Apr-1999 105.25 106.01 105.90 103.65 104.40 104.30 22
May-1999 104.82 104.95 105.12 108.15 108.29 108.46 21
Jun-1999 112.64 107.98 107.52 110.93 106.34 105.90 22
Jul-1999  64.10  61.14  59.83  63.13  60.21  58.93 22
Aug-1999 104.35 105.44 105.51 102.77 103.85 103.91 22
Sep-1999 107.03 107.56 107.84 105.40 105.93 106.21 22
Oct-1999 106.81 107.97 108.06 110.20 111.40 111.49 21
Nov-1999  99.36  99.06  99.34  97.86  97.56  97.84 22
Dec-1999  87.88  89.53  89.60  82.79  84.34  84.40 23
Jan-2000  94.51  93.98  94.20  97.52  96.97  97.19 21
Feb-2000 104.60 106.01 106.32 107.92 109.37 109.69 21
Mar-2000 118.43 119.47 119.80 111.56 112.54 112.86 23
Apr-2000  94.45  94.87  94.78 102.32 102.78 102.68 20
May-2000 109.60 110.03 110.17 103.24 103.65 103.79 23
Jun-2000 112.26 110.68 110.40 110.56 109.01 108.73 22
Jul-2000  61.42  58.05  56.76  63.37  59.90  58.56 21
Aug-2000 110.06 109.84 109.90 103.68 103.47 103.53 23
Sep-2000 102.35 101.59 101.80 105.60 104.81 105.03 21
Oct-2000 111.53 113.30 113.41 109.84 111.58 111.69 22
Nov-2000  99.72  99.39  99.67  98.20  97.88  98.16 22
Dec-2000  82.21  84.08  84.16  84.82  86.75  86.83 21
Jan-2001  99.55  98.31  98.47  93.78  92.61  92.76 23
Feb-2001  99.63 100.81 101.10 107.93 109.21 109.52 20
Mar-2001 112.93 114.22 114.56 111.22 112.49 112.82 22
Apr-2001  99.57  99.74  99.64 102.73 102.91 102.80 21
May-2001 114.24 115.23 115.36 107.62 108.55 108.68 23
Jun-2001 106.66 105.36 105.11 110.04 108.71 108.45 21
Jul-2001  64.88  61.47  60.10  63.90  60.53  59.19 22
Aug-2001 111.00 110.71 110.84 104.56 104.29 104.41 23
Sep-2001  97.72  96.43  96.63 105.87 104.46 104.68 20
Oct-2001 116.41 118.52 118.64 109.66 111.65 111.76 23
Nov-2001  99.72  99.65  99.94  98.21  98.14  98.42 22
Dec-2001  76.84  78.68  78.77  79.28  81.18  81.27 21
Jan-2002  99.99  97.84  97.92  94.19  92.17  92.24 23
Feb-2002  99.63 100.69 100.96 107.94 109.08 109.37 20
Mar-2002 102.30 103.76 104.07 105.55 107.05 107.37 21
Apr-2002 109.72 109.79 109.68 108.06 108.13 108.01 22
May-2002 113.41 114.92 115.04 106.84 108.26 108.38 23
Jun-2002 101.38 100.36 100.18 109.83 108.72 108.52 20
Jul-2002  68.64  65.18  63.76  64.66  61.40  60.06 23
Aug-2002 104.22 104.23 104.41 102.64 102.65 102.83 22
Sep-2002 103.12 101.60 101.80 106.39 104.82 105.03 21
Oct-2002 116.43 118.18 118.27 109.68 111.33 111.41 23
Nov-2002  89.43  89.33  89.60  92.27  92.17  92.44 21
Dec-2002  76.73  78.62  78.69  75.56  77.43  77.49 22
Jan-2003 100.37  97.32  97.32  94.55  91.68  91.68 23
Feb-2003  99.62 100.61 100.88 107.92 108.99 109.28 20
Mar-2003 107.22 108.79 109.10 110.62 112.25 112.56 21
Apr-2003 103.92 104.33 104.21 102.35 102.75 102.63 22
May-2003 107.32 109.29 109.40 105.69 107.64 107.74 22
Jun-2003 102.55 102.06 101.95 105.80 105.30 105.19 21
Jul-2003  69.66  66.33  64.98  65.62  62.49  61.21 23
Aug-2003 102.11 101.98 102.20 105.35 105.22 105.44 21
Sep-2003 108.50 106.79 106.99 106.86 105.17 105.36 22
Oct-2003 116.60 117.45 117.51 109.84 110.64 110.70 23
Nov-2003  91.05  91.03  91.31  98.64  98.62  98.92 20
Dec-2003  87.00  89.33  89.36  81.95  84.15  84.18 23
Jan-2004  92.48  89.04  88.97  91.08  87.69  87.62 22
Feb-2004  99.86 100.72 100.97 108.18 109.11 109.38 20
Mar-2004 117.45 119.18 119.50 110.64 112.27 112.57 23
Apr-2004 104.58 105.40 105.30 102.99 103.80 103.70 22
May-2004  99.47 101.74 101.85 102.63 104.97 105.09 21
Jun-2004 110.71 110.81 110.74 109.04 109.13 109.06 22
Jul-2004  67.68  64.66  63.43  66.65  63.68  62.47 22
Aug-2004 107.27 106.72 106.98 105.65 105.10 105.36 22
Sep-2004 108.48 107.13 107.34 106.84 105.50 105.71 22
Oct-2004 106.71 106.44 106.45 110.10 109.82 109.83 21
Nov-2004  97.98  98.09  98.44  96.50  96.60  96.95 22
Dec-2004  87.10  89.38  89.34  82.05  84.20  84.16 23
Jan-2005  97.54  93.54  93.40 100.64  96.51  96.37 21
Feb-2005 100.31 100.85 101.07 108.66 109.26 109.49 20
Mar-2005 108.74 110.44 110.72 102.44 104.04 104.30 23
Apr-2005 107.02 108.20 108.12 110.42 111.64 111.55 21
May-2005 103.54 106.28 106.41 101.98 104.67 104.80 22
Jun-2005 109.95 110.99 110.99 108.28 109.31 109.31 22
Jul-2005  65.56  63.05  61.95  67.64  65.05  63.92 21
Aug-2005 112.53 111.20 111.49 106.01 104.76 105.03 23
Sep-2005 107.96 106.79 107.02 106.33 105.17 105.40 22
Oct-2005 107.33 106.10 106.06 110.73 109.47 109.43 21
Nov-2005  94.33  94.34  94.68  92.90  92.91  93.25 22
Dec-2005  86.91  89.08  88.96  85.60  87.73  87.62 22
Jan-2006  97.58  93.53  93.38  96.10  92.11  91.97 22
Feb-2006 100.57 101.18 101.37 108.95 109.62 109.81 20
Mar-2006 117.50 119.56 119.86 110.69 112.63 112.91 23
Apr-2006  92.52  93.53  93.47 100.23 101.32 101.26 20
May-2006 109.49 112.40 112.57 103.15 105.88 106.05 23
Jun-2006 109.12 110.87 110.88 107.47 109.19 109.20 22
Jul-2006  65.89  64.17  63.11  67.98  66.21  65.12 21
Aug-2006 113.12 111.02 111.34 106.57 104.58 104.89 23
Sep-2006 103.57 102.68 102.93 106.86 105.94 106.20 21
Oct-2006 113.33 111.10 111.03 111.61 109.42 109.34 22
Nov-2006  97.84  97.67  98.02  96.36  96.19  96.53 22
Dec-2006  81.66  83.45  83.29  84.25  86.10  85.94 21
Jan-2007 102.43  98.40  98.20  96.49  92.69  92.51 23
Feb-2007 100.80 101.47 101.65 109.20 109.92 110.12 20
Mar-2007 112.32 114.56 114.83 110.62 112.82 113.09 22
Apr-2007  96.93  97.91  97.84 100.01 101.02 100.95 21
May-2007 108.84 111.79 111.96 102.53 105.31 105.47 23
Jun-2007 103.39 105.79 105.85 106.67 109.15 109.21 21
Jul-2007  70.75  69.49  68.46  69.68  68.43  67.42 22
Aug-2007 113.81 110.94 111.32 107.21 104.51 104.86 23
Sep-2007  98.19  97.37  97.60 106.38 105.48 105.73 20
Oct-2007 119.31 116.46 116.38 112.39 109.71 109.64 23
Nov-2007 101.80 101.33 101.64 100.26  99.80 100.10 22
Dec-2007  76.29  78.01  77.81  78.72  80.49  80.28 21
Jan-2008 102.91  98.67  98.46  96.95  92.95  92.75 23
Feb-2008 105.74 106.76 106.97 109.10 110.15 110.37 21
Mar-2008  99.05 101.12 101.36 102.20 104.33 104.58 21
Apr-2008 109.78 111.04 110.95 108.12 109.36 109.27 22
May-2008 102.02 104.64 104.78 100.47 103.05 103.19 22
Jun-2008 103.08 105.69 105.77 106.35 109.04 109.13 21
Jul-2008  74.96  74.42  73.45  70.62  70.11  69.20 23
Aug-2008 103.68 100.62 101.01 106.97 103.82 104.22 21
Sep-2008 108.21 107.37 107.61 106.57 105.74 105.98 22
Oct-2008 119.92 116.37 116.28 112.97 109.62 109.54 23
Nov-2008  87.94  87.50  87.74  95.27  94.79  95.05 20
Dec-2008  86.40  88.37  88.08  81.39  83.25  82.97 23
Jan-2009  93.48  89.52  89.36  92.07  88.17  88.01 22
Feb-2009 100.47 101.48 101.68 108.84 109.94 110.15 20
Mar-2009 112.45 114.91 115.16 110.75 113.17 113.42 22
Apr-2009 102.07 103.49 103.38 100.52 101.92 101.82 22
May-2009  96.65  99.24  99.38  99.72 102.39 102.54 21
Jun-2009 107.98 110.52 110.62 106.35 108.85 108.94 22
Jul-2009  76.15  76.21  75.35  71.73  71.79  70.98 23
Aug-2009 104.49 101.32 101.74 107.81 104.54 104.97 21
Sep-2009 107.09 106.14 106.32 105.47 104.53 104.71 22
Oct-2009 114.74 110.68 110.58 113.01 109.01 108.90 22
Nov-2009  96.77  96.28  96.53  99.84  99.34  99.59 21
Dec-2009  86.54  88.54  88.19  81.52  83.41  83.08 23
Jan-2010  93.54  89.67  89.59  96.51  92.51  92.43 21
Feb-2010 100.00 101.16 101.35 108.33 109.59 109.79 20
Mar-2010 117.58 120.19 120.42 110.76 113.22 113.44 23
Apr-2010 103.48 105.27 105.14 101.91 103.67 103.54 22
May-2010  97.92 100.41 100.56 101.03 103.60 103.75 21
Jun-2010 108.09 109.91 109.96 106.45 108.25 108.30 22
Jul-2010  73.94  74.64  73.93  72.82  73.51  72.81 22
Aug-2010 109.34 105.94 106.39 107.68 104.34 104.78 22
Sep-2010 107.38 106.59 106.74 105.75 104.98 105.13 22
Oct-2010 109.46 105.23 105.11 112.93 108.57 108.45 21
Nov-2010  98.93  98.31  98.56  97.43  96.82  97.07 22
Dec-2010  86.52  88.38  88.00  81.50  83.26  82.90 23
Jan-2011  98.26  94.79  94.78 101.38  97.79  97.79 21
Feb-2011  99.75 100.90 101.10 108.06 109.31 109.53 20
Mar-2011 117.65 120.20 120.40 110.83 113.24 113.42 23
Apr-2011  98.22 100.01  99.87 101.34 103.19 103.04 21
May-2011 102.74 105.24 105.37 101.18 103.65 103.77 22
Jun-2011 108.03 109.12 109.11 106.39 107.47 107.46 22
Jul-2011  71.57  72.90  72.33  73.84  75.21  74.62 21
Aug-2011 114.26 110.51 110.98 107.64 104.11 104.54 23
Sep-2011 107.10 106.19 106.31 105.47 104.58 104.70 22
Oct-2011 109.21 105.15 105.04 112.67 108.49 108.37 21
Nov-2011  99.11  98.20  98.45  97.61  96.71  96.96 22
Dec-2011  86.44  88.24  87.84  85.13  86.90  86.51 22
Jan-2012  97.93  95.34  95.41  96.45  93.89  93.96 22
Feb-2012 104.56 105.77 105.97 107.88 109.13 109.33 21
Mar-2012 112.15 114.83 114.99 110.45 113.09 113.25 22
Apr-2012  98.41  99.90  99.76 101.53 103.07 102.93 21
May-2012 108.10 109.92 110.02 101.84 103.54 103.64 23
Jun-2012 103.11 103.55 103.45 106.38 106.84 106.74 21
Jul-2012  75.98  78.09  77.55  74.83  76.91  76.38 22
Aug-2012 114.26 110.39 110.86 107.64 103.99 104.43 23
Sep-2012  96.51  95.89  95.97 104.56 103.88 103.97 20
Oct-2012 119.22 115.49 115.40 112.31 108.79 108.71 23
Nov-2012  99.31  97.81  98.06  97.80  96.33  96.57 22
Dec-2012  76.02  77.58  77.25  78.44  80.04  79.70 21
Jan-2013 102.55 100.53 100.68  96.60  94.71  94.84 23
Feb-2013  99.56 100.64 100.84 107.85 109.03 109.24 20
Mar-2013 101.47 104.22 104.36 104.69 107.53 107.67 21
Apr-2013 108.73 109.95 109.77 107.08 108.28 108.10 22
May-2013 108.57 109.48 109.52 102.28 103.14 103.17 23
Jun-2013  98.46  98.28  98.14 106.67 106.47 106.32 20
Jul-2013  80.05  83.11  82.58  75.41  78.29  77.80 23
Aug-2013 109.36 105.65 106.10 107.70 104.05 104.49 22
Sep-2013 101.06 100.52 100.57 104.27 103.71 103.76 21
Oct-2013 118.55 115.91 115.88 111.67 109.19 109.16 23
Nov-2013  97.76  95.41  95.62 100.86  98.43  98.65 21
Dec-2013  75.99  77.53  77.25  74.83  76.36  76.08 22
Jan-2014 102.34 100.75 100.96  96.41  94.91  95.11 23
Feb-2014  99.35 100.62 100.83 107.63 109.01 109.23 20
Mar-2014 105.84 109.16 109.30 109.20 112.63 112.77 21
Apr-2014 104.55 105.35 105.14 102.96 103.75 103.55 22
May-2014 104.06 104.11 104.10 102.49 102.54 102.52 22
Jun-2014 103.75 102.89 102.69 107.04 106.15 105.95 21
Jul-2014  80.37  83.98  83.49  75.71  79.11  78.65 23
Aug-2014 104.52 100.96 101.39 107.83 104.16 104.61 21
Sep-2014 105.36 105.12 105.11 103.77 103.53 103.52 22
Oct-2014 117.73 116.09 116.12 110.91 109.36 109.39 23
Nov-2014  89.30  86.76  86.93  96.75  93.99  94.18 20
Dec-2014  86.39  87.99  87.73  81.38  82.88  82.65 23
Jan-2015  92.85  91.39  91.63  91.44  90.00  90.24 22
Feb-2015  99.08 100.63 100.86 107.33 109.01 109.26 20
Mar-2015 110.27 113.88 113.99 108.59 112.15 112.26 22
Apr-2015 105.00 105.76 105.50 103.41 104.16 103.90 22
May-2015  99.24  98.94  98.87 102.39 102.08 102.00 21
Jun-2015 109.21 107.62 107.40 107.56 105.98 105.77 22
Jul-2015  80.77  84.59  84.11  76.09  79.69  79.23 23
Aug-2015 104.45 100.99 101.43 107.77 104.20 104.65 21
Sep-2015 104.96 104.73 104.67 103.37 103.14 103.08 22
Oct-2015 111.80 111.06 111.14 110.11 109.38 109.45 22
Nov-2015  98.25  95.22  95.41 101.37  98.24  98.44 21
Dec-2015  86.65  88.24  88.05  81.63  83.13  82.94 23
Jan-2016  92.81  91.29  91.54  95.75  94.18  94.45 21
Feb-2016 103.79 105.64 105.88 107.09 108.99 109.25 21
Mar-2016 106.67 110.20 110.30 100.49 103.81 103.90 23
Apr-2016 105.39 106.10 105.81 108.74 109.46 109.17 21
May-2016 104.36 103.77 103.67 102.78 102.20 102.10 22
Jun-2016 109.61 107.45 107.20 107.95 105.82 105.58 22
Jul-2016  73.54  77.25  76.81  75.87  79.70  79.24 21
Aug-2016 114.40 110.51 110.98 107.76 104.10 104.55 23
Sep-2016 104.83 104.71 104.64 103.24 103.12 103.06 22
Oct-2016 106.08 105.90 105.99 109.44 109.27 109.35 21
Nov-2016 100.33  97.22  97.46  98.81  95.75  95.98 22
Dec-2016  87.01  88.39  88.23  85.70  87.05  86.90 22
Jan-2017  97.48  96.06  96.33  96.00  94.61  94.87 22
Feb-2017  98.70 100.49 100.71 106.92 108.86 109.10 20
Mar-2017 114.21 118.18 118.28 107.59 111.33 111.42 23
Apr-2017  92.48  92.95  92.69 100.19 100.69 100.41 20
May-2017 109.65 108.75 108.64 103.29 102.45 102.34 23
Jun-2017 109.84 107.28 107.03 108.18 105.66 105.40 22
Jul-2017  73.67  77.64  77.19  76.01  80.10  79.64 21
Aug-2017 114.44 110.34 110.78 107.80 103.95 104.35 23
Sep-2017  99.64  99.69  99.62 102.80 102.85 102.79 21
Oct-2017 110.62 111.05 111.15 108.94 109.36 109.47 22
Nov-2017 103.84 100.35 100.62 102.27  98.83  99.10 22
Dec-2017  82.15  83.16  83.05  84.76  85.80  85.68 21
Jan-2018 102.00 100.98 101.25  96.09  95.13  95.38 23
Feb-2018  98.57 100.51 100.72 106.78 108.89 109.12 20
Mar-2018 103.83 107.69 107.76 102.25 106.06 106.13 22
Apr-2018 103.06 103.25 102.97 106.33 106.53 106.24 21
May-2018 110.08 108.56 108.41 103.70 102.27 102.12 23
Jun-2018 104.71 102.30 102.05 108.04 105.55 105.29 21
Jul-2018  77.29  81.82  81.36  76.12  80.58  80.13 22
Aug-2018 114.70 110.15 110.55 108.05 103.77 104.14 23
Sep-2018  94.36  94.70  94.64 102.23 102.59 102.53 20
Oct-2018 115.64 116.48 116.61 108.93 109.72 109.85 23
Nov-2018 100.43  96.77  97.05  98.91  95.30  95.58 22
Dec-2018  77.07  77.90  77.81  79.51  80.37  80.28 21
Jan-2019 101.89 101.11 101.37  95.98  95.25  95.49 23
Feb-2019  98.65 100.72 100.93 106.88 109.12 109.35 20
Mar-2019 103.30 107.49 107.55 106.58 110.90 110.96 21
Apr-2019 103.49 103.44 103.17 101.93 101.87 101.61 22
May-2019 110.32 108.22 108.04 103.93 101.94 101.78 23
Jun-2019  99.75  97.63  97.40 108.06 105.77 105.51 20


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Last Update: March 16, 2018