Seasonal Lag#
The offset to the same point in a previous season, used in seasonal models.
Important
✨ AI-generated content. This page was written with the assistance of an AI language model and is provided as a learning aid. Despite careful review, it may still contain mistakes, omissions, or out-of-date information. Whether you are new to the topic, a team lead, or a senior practitioner, treat it as a starting point rather than an authoritative reference: read it critically and independently verify anything you act on (code, commands, figures, and factual claims) against official documentation and primary sources before relying on it.
What it is#
A lag is a past value of the series, \(y_{t-k}\); the seasonal lag is the lag equal to the seasonal period \(m\) — the value from the same point one cycle ago:
Common periods#
The period is set by the calendar of the data: \(m = 12\) for monthly data with yearly seasonality, \(m = 7\) for daily data with weekly seasonality, \(m = 24\) for hourly data with daily cycles.
Where it’s used#
The seasonal lag underlies the seasonal naïve forecast (\(\hat{y}_t = y_{t-m}\)), seasonal differencing (which strips out seasonality), and lag features in ML forecasting. A large autocorrelation at the seasonal lag is the signature of seasonality.
Theme: Signal Processing & Time Series · All terminology
Hint
Mind map — connected ideas
Time Series Forecasting · Seasonality · Naïve Baseline Forecast · Log-Space · Temporal autocorrelation (Serial Correlation) · Simple Baseline Methods
Hint
More in Signal Processing & Time Series
ARIMA (AutoRegressive Integrated Moving Average) · Bayesian Time Series · Forecast Error · Forecasting Benchmarks · Forecasting Competitions · Log-Space · Low-pass Filtering · LSTM — Long Short-Term Memory Networks · M-Competitions (Makridakis Competitions) · Naïve Baseline Forecast · Prophet — Time Series Forecasting by Facebook (Meta) · Seasonality · Signal Processing · Simple Baseline Methods
See also
Source article Adapted (context, re-expressed) in our own words from: Seasonal Lag (insightful-data-lab.com).