BaliProof publishes educational buyer-side guides for foreign buyers researching Bali villas and property ownership.

Our content is prepared from research packs, market observations, buyer questions, and editorial review. Legal, tax, and investment details are treated as educational context rather than transaction-specific advice.

Before acting on any property decision, buyers should verify documents with an independent Indonesian notary or lawyer and request current availability, ownership terms, permits, and cost breakdowns from the seller or authorized representative.

Climate Data Methodology

Climate sections use the Copernicus Climate Change Service ERA5-Land hourly time-series dataset, licensed under CC BY 4.0. The analysis covers complete calendar years from 2015 through 2025 and converts UTC source timestamps to Asia/Makassar local time before daily, monthly, and annual aggregation.

ERA5-Land is an hourly reanalysis on a 0.1° × 0.1° grid, approximately 9 km. We use one representative grid point for each stated area. These are model estimates for an area—not weather-station readings at a villa, parcel-level measurements, or evidence of a building outcome.

The source variables are 2 m air temperature, 2 m dew-point temperature, surface pressure, de-accumulated total precipitation, downward surface solar radiation, first-layer volumetric soil water, and the eastward and northward components of 10 m wind. We derive:

  • relative humidity from air temperature and dew point using the Magnus formula;
  • wind speed from the two wind components;
  • wet-bulb temperature using the Stull approximation;
  • daily reference evapotranspiration using the FAO-56 Penman–Monteith method.

The fixed screening thresholds are at least 1 mm of precipitation for a rainy day, at least 85% relative humidity for a high-humidity hour, at least six such hours for a high-humidity day, and at least one hourly 10 m wind-speed value of 30 km/h for a strong-wind day. The wind threshold is a comparison screen, not a damage threshold.

The four published indices are relative comparisons among five configured Bali location requests, which resolve to four distinct populated ERA5-Land cells:

  • Rain Burden: annual rainfall 45%, rainy days 35%, longest wet period 20%;
  • Humidity Burden: average relative humidity 50%, high-humidity hours 50%;
  • Outdoor Maintenance Pressure: Rain Burden 35%, Humidity Burden 35%, strong-wind days 15%, solar exposure 15%;
  • Seasonal Weather Stability: inverse of combined monthly rainfall variation 70% and daily-temperature variability 30%.

Every index is presented alongside its supporting raw metrics. It is not an engineering, insurance, maintenance-cost, yield, damage, mould, corrosion, salt-deposition, or flood-risk rating. Actual exposure still depends on elevation, drainage, shade, materials, roof form, ventilation, construction quality, sea proximity, and maintenance history, all of which require property-level inspection.