Background
The wilaya of Sa{\"\i}da, located in the semi-arid steppe of northwestern Algeria, comprises seven administrative communes distributed across a heterogeneous topography. Characterizing the long-term climatic trends and geographic setting of this region is essential background for interpreting the transmission dynamics of cutaneous leishmaniasis (CL) and other environmentally sensitive vector-borne diseases in the area.
Aims
This study aimed to (i) geographically characterize the seven communes of the wilaya of Sa{\"\i}da (Sa{\"\i}da City, Hassasna, Maamora, Skhouna, Balloul, Tircine, and A{\"\i}n Soltane), and (ii) analyze the 24-year (2002{\textendash}2025) trends in temperature and precipitation across the region. Materials and Methods Geographic coordinates of the seven communes were determined and mapped, distinguishing the single urban commune (Sa{\"\i}da City, the wilaya capital) from the six rural communes. A continuous monthly series of mean temperature ({\textdegree}C) and total precipitation (mm) covering 288 months (January 2002{\textendash}December 2025) was compiled and subjected to a systematic data-quality audit; two physically implausible monthly precipitation values and seven duplicate-flagged months were identified and excluded from the analytic series. Annual and seasonal climatology were described, and temporal trends were assessed using the Mann-Kendall test, Sen{\textquoteright}s slope estimator, and linear regression (slope with 95\% confidence interval).
Results
The wilaya spans approximately 34.50{\textendash}34.99{\textdegree}N and 0.15{\textendash}0.85{\textdegree}E, located roughly 180 km southeast of Oran, with Skhouna representing the most geographically distant rural commune from the urban center. Annual mean temperature rose significantly over the study period (+ 0.103{\textdegree}C/year, 95\% CI 0.053{\textendash}0.153; p = 0.0028), corresponding to an approximate + 2.4{\textdegree}C increase between 2002 and 2025. Annual total precipitation showed a probable declining trend (- 6.1 mm/year, 95\% CI - 11.7 to - 0.6; p = 0.043), representing roughly a one-third reduction in annual rainfall totals over the same period. The regional climate followed a classical semi-arid Mediterranean pattern, with hot, dry summers (24{\textendash}28{\textdegree}C, \< 20 mm/month) and cooler, comparatively wetter autumn{\textendash}winter{\textendash}spring months. These findings are significant beyond their descriptive value: the magnitude of the warming trend places Sa{\"\i}da among the more rapidly warming semi-arid zones of the Mediterranean basin, with plausible relevance to the seasonal activity window of phlebotomine sand fly vectors, while the locally-calibrated seasonal climatology established here provides, for the first time for this wilaya, a climatic reference against which the monthly CL reporting pattern can be meaningfully interpreted.
Conclusion
The wilaya of Sa{\"\i}da has undergone a statistically robust warming trend and a probable drying trend over the past 24 years, consistent with broader Mediterranean and North African climate observations. These geo-climatic findings offer practical applications for CL prevention: anchoring vector-control campaign timing to the pre-transmission warm season rather than the later diagnostic-peak months, supporting periodic reassessment of the transmission season{\textquoteright}s boundaries as warming continues, prioritizing surveillance resources geographically as reservoir habitat suitability shifts, and establishing a locally-validated baseline for detecting future climatic anomalies that may warrant heightened CL surveillance.
}, year = {2026}, pages = {1 - 21}, month = {08/2026}, publisher = {Springer Science and Business Media LLC}, url = {https://assets-eu.researchsquare.com/files/rs-10482904/v1_covered_ec2deff0-28d1-4135-b726-50de7c5c3361.pdf?c=1786098547}, doi = {10.21203/rs.3.rs-10482904/v1}, language = {ENG}, }