Western Australia Rainfall Projections at 20km Resolution

Rainfall projections provide monthly average precipitation in mm/day for Western Australia at a 20-kilometre resolution. The dataset includes annual and seasonal data for five time periods from 1990-2099 under two emissions scenarios, derived from a 10-model ensemble. It was produced by the Department of Water and Environmental Regulation's Climate Science Initiative.

Use Cases

• Model future water resource availability by analyzing precipitation changes between the Baseline (1990-2009) and 2090 (2080 2099) periods.
• Compare climate outcomes under SSP1-2.6 and SSP3-7.0 emissions scenarios using the ensemble mean, minimum, and maximum results.
• Assess seasonal rainfall variability for Summer, Autumn, Winter, and Spring using the provided standard deviation values.
• Calculate relative change in rainfall patterns using the difference files between future and baseline predictions.

Strengths

• Data is bias-corrected to improve accuracy for hydrological applications.
• Projections cover five distinct time periods spanning over a century, from 1990 to 2099.
• Results represent a 10-model ensemble, providing mean, minimum, maximum, and standard deviation outputs.
• Available at a consistent 20-kilometre spatial resolution for the entire state.

Limitations

• Projections are limited to two emissions scenarios (SSP1-2.6 and SSP3-7.0), lacking a middle-of-the-road scenario.
• The 20km resolution may be too coarse for localized planning or microclimate analysis.
• Data limitations and appropriate usage requirements are detailed in a separate technical fact sheet, requiring user review.

Provenance

Source

Department of Water and Environmental Regulation, Climate Science Initiative.

Collection Method

Bias-corrected projections derived from the NSW and Australian Regional Climate Modelling (NARCliM) ensemble of 10 Global Climate Models.

Time Range

1990-2099, with slices for Baseline (1990-2009), 2030, 2050, 2070, and 2090.

Freshness

Last updated March 2026.

Geography

Western Australia, Australia.