Clustering Methods for Identifying and Modelling Areas with Similar Temperature Variations
Edoardo Otranto
TL;DR
The paper addresses how to improve modelling of global temperature dynamics by identifying groups of countries with similar temporal behavior. It introduces three clustering schemes based on annual warming rates, annual temperature variations, and the persistence of the sign of changes, using Euclidean distances for the first two and a Hamming distance for signs. It then constructs six distance- or cluster-based spatial weight matrices for Space-Time AutoRegressive (STAR) models and compares them against a contiguity-based baseline, finding that distance-based weights yield superior in-sample and out-of-sample forecasts, with the Hamming-based weights delivering the strongest in-sample fit and the Euclidean distance on full distances (dA) offering the best out-of-sample performance. The results showcase that statistical similarity among countries can outperform geographic proximity in capturing temperature dynamics and suggest broader applicability to other environmental and socioeconomic datasets.
Abstract
This paper proposes a novel data-driven approach for identifying and modelling areas with similar temperature variations throufigureh clustering and Space-Time AutoRegressive (STAR) models. Using annual temperature data from 168 countries (1901-2022), we apply three clustering methods based on (i) warming rates, (ii) annual temperature variations, and (iii) persistence of variation signs, using Euclidean and Hamming distances. These clusters are then employed to construct alternative spatial weight matrices for STAR models. Empirical results show that distance-based STAR models outperform classical contiguity-based ones, both in-sample and out-of-sample, with the Hamming distance-based STAR model achieving the best predictive accuracy. The study demonstrates that using statistical similarity rather than geographical proximity improves the modelling of global temperature dynamics, suggesting broader applicability to other environmental and socioeconomic datasets.
