Industrial Production and Capacity Utilization - G.17

Federal Reserve Seasonal Factors for Domestic Auto and Truck Production

Release Date: March 18, 2025

Seasonal factors for auto and truck production were revised from January 2020 through September 2026 on March 18, 2025. The revised factors for September 2024 through February 2025 were used in the G.17 release issued on March 18, 2025, and the revised factors for earlier months will be incorporated into the production estimates at the time of the annual revision. The revised seasonal factors are based on production data through January 2025; in the estimation, production data for January 2024 and January 2025 are identified as outliers due to unseasonably cold weather and the impact of snow storms. The seasonal factors are scheduled to be revised again in March 2026.

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
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  		Regular Seasonal Factors Weekday-basis Seasonal Factors
 
Autos 		Total
Trucks 		Light
Trucks 		 
Autos 		Total
Trucks 		Light
Trucks 		 
Weekdays
Jan-2019 101.31  99.46  99.47  95.43  93.69  93.71 23
Feb-2019 100.06 100.26 100.63 108.39 108.62 109.01 20
Mar-2019 102.69 108.73 108.92 105.95 112.18 112.38 21
Apr-2019 103.86 101.80 101.56 102.29 100.26 100.03 22
May-2019 107.01 105.76 105.63 100.81  99.63  99.50 23
Jun-2019  96.50  96.45  96.35 104.54 104.49 104.38 20
Jul-2019  83.58  88.17  87.79  78.73  83.05  82.70 23
Aug-2019 107.47 107.95 108.48 105.84 106.31 106.83 22
Sep-2019 100.56  99.75  99.60 103.75 102.91 102.76 21
Oct-2019 117.69 115.88 115.91 110.87 109.17 109.19 23
Nov-2019 100.57  96.89  97.00 103.76  99.97 100.08 21
Dec-2019  83.41  83.88  83.65  82.15  82.61  82.38 22
Jan-2020 101.08  99.00  99.06  95.22  93.26  93.32 23
Feb-2020 100.26 100.27 100.62 108.61 108.63 109.00 20
Mar-2020 108.03 114.61 114.79 106.39 112.88 113.05 22
Apr-2020 103.40 101.83 101.61 101.84 100.29 100.07 22
May-2020  96.90  96.00  95.90  99.98  99.04  98.94 21
Jun-2020 105.70 106.28 106.18 104.10 104.67 104.57 22
Jul-2020  82.65  89.27  88.92  77.86  84.09  83.76 23
Aug-2020 102.81 103.02 103.55 106.07 106.29 106.84 21
Sep-2020 106.12 104.65 104.52 104.51 103.07 102.93 22
Oct-2020 113.39 109.54 109.52 111.67 107.88 107.86 22
Nov-2020  96.59  92.36  92.46  99.65  95.29  95.39 21
Dec-2020  87.78  88.57  88.28  82.69  83.43  83.16 23
Jan-2021  91.15  89.52  89.57  94.04  92.36  92.41 21
Feb-2021 100.30 100.12 100.46 108.65 108.47 108.83 20
Mar-2021 113.17 119.98 120.16 106.61 113.03 113.19 23
Apr-2021 102.85 101.58 101.38 101.29 100.04  99.84 22
May-2021  96.47  95.84  95.77  99.53  98.88  98.81 21
Jun-2021 105.64 106.12 106.02 104.04 104.52 104.42 22
Jul-2021  78.86  86.16  85.87  77.66  84.86  84.57 22
Aug-2021 107.76 108.13 108.70 106.13 106.49 107.06 22
Sep-2021 106.66 104.58 104.44 105.05 102.99 102.86 22
Oct-2021 108.73 103.89 103.84 112.18 107.19 107.13 21
Nov-2021 102.22  97.64  97.74 100.67  96.16  96.26 22
Dec-2021  87.54  88.48  88.15  82.47  83.35  83.04 23
Jan-2022  95.53  93.99  94.05  98.57  96.97  97.04 21
Feb-2022 100.01  99.79 100.13 108.35 108.11 108.47 20
Mar-2022 113.13 119.96 120.13 106.57 113.01 113.16 23
Apr-2022  97.29  96.34  96.16 100.38  99.40  99.21 21
May-2022 101.05 100.85 100.81  99.52  99.32  99.28 22
Jun-2022 105.34 105.80 105.69 103.74 104.20 104.09 22
Jul-2022  75.52  83.12  82.91  77.91  85.75  85.54 21
Aug-2022 112.89 113.20 113.79 106.34 106.63 107.20 23
Sep-2022 107.11 104.30 104.15 105.49 102.72 102.57 22
Oct-2022 109.10 103.41 103.32 112.57 106.70 106.60 21
Nov-2022 103.07  98.60  98.68 101.51  97.11  97.19 22
Dec-2022  87.13  88.19  87.82  85.81  86.85  86.49 22
Jan-2023  95.38  94.05  94.13  93.94  92.62  92.71 22
Feb-2023  99.86  99.50  99.82 108.18 107.79 108.14 20
Mar-2023 113.36 119.89 120.04 106.79 112.94 113.08 23
Apr-2023  91.87  91.32  91.17  99.52  98.93  98.77 20
May-2023 105.40 105.91 105.89  99.29  99.77  99.76 23
Jun-2023 105.21 105.38 105.26 103.62 103.78 103.66 22
Jul-2023  72.03  79.87  79.73  74.31  82.40  82.26 21
Aug-2023 113.13 113.30 113.92 106.57 106.73 107.31 23
Sep-2023 102.42  99.07  98.92 105.67 102.22 102.06 21
Oct-2023 114.62 107.99 107.85 112.89 106.35 106.21 22
Nov-2023 102.87  98.32  98.38 101.31  96.83  96.89 22
Dec-2023  81.62  82.82  82.45  84.21  85.45  85.06 21
Jan-2024  99.79  98.80  98.93  94.01  93.07  93.19 23
Feb-2024 104.48 104.00 104.31 107.79 107.30 107.63 21
Mar-2024  98.75 104.09 104.22 101.89 107.40 107.53 21
Apr-2024 106.65 106.34 106.19 105.03 104.73 104.59 22
May-2024 105.22 106.35 106.37  99.12 100.19 100.20 23
Jun-2024  92.95  92.88  92.75 100.69 100.62 100.48 20
Jul-2024  83.40  93.18  93.06  78.57  87.78  87.67 23
Aug-2024 108.61 108.27 108.88 106.96 106.63 107.23 22
Sep-2024 102.72  99.00  98.83 105.98 102.14 101.97 21
Oct-2024 120.24 112.78 112.61 113.27 106.24 106.08 23
Nov-2024  98.12  93.67  93.71 101.24  96.64  96.69 21
Dec-2024  76.13  77.43  77.04  74.97  76.26  75.88 22
Jan-2025  97.04  96.74  96.91  91.42  91.13  91.30 23
Feb-2025  99.20  98.50  98.78 107.46 106.71 107.01 20
Mar-2025 104.17 109.08 109.20 107.48 112.55 112.66 21
Apr-2025 101.70 101.82 101.71 100.16 100.28 100.17 22
May-2025 100.30 101.92 101.97  98.78 100.37 100.43 22
Jun-2025  97.63  97.40  97.24 100.73 100.50 100.32 21
Jul-2025  83.10  93.61  93.50  78.28  88.18  88.08 23
Aug-2025 104.00 103.23 103.83 107.30 106.51 107.13 21
Sep-2025 108.25 104.06 103.88 106.61 102.48 102.30 22
Oct-2025 120.71 112.69 112.50 113.71 106.16 105.98 23
Nov-2025  95.59  91.14  91.19 103.56  98.74  98.79 20
Dec-2025  85.82  87.53  87.07  80.85  82.45  82.02 23
Jan-2026  87.38  87.54  87.71  86.06  86.21  86.38 22
Feb-2026  99.17  98.33  98.59 107.44 106.52 106.80 20
Mar-2026 109.58 114.01 114.11 107.91 112.28 112.38 22
Apr-2026  99.11  99.71  99.62  97.61  98.20  98.11 22
May-2026  95.53  97.26  97.35  98.57 100.35 100.44 21
Jun-2026  97.77  97.42  97.24  96.29  95.94  95.76 22
Jul-2026  82.92  94.05  93.96  78.11  88.60  88.51 23
Aug-2026 104.17 103.02 103.59 107.48 106.29 106.88 21
Sep-2026 108.49   103.89 106.84   102.32 22

Last Update: March 18, 2025