About the service

Data sources

maalataanko.fi combines forecasts from two trusted weather services to assess painting conditions:

• YR.no Locationforecast 2.0 — open weather forecast API from the Norwegian Meteorological Institute (MET Norway). Primary source for temperature, humidity, wind, and precipitation.
• Finnish Meteorological Institute (FMI) — HARMONIE model forecasts and edited forecasts. Provides precipitation probability and frost risk used to enrich YR.no data.
• Paint manufacturer technical data sheets (TDS) — Tikkurila, Teknos, Cello, and Uula. Product-specific painting condition thresholds are derived from official manufacturer guidelines.

How the assessment works

The service fetches a weather forecast for the selected location and divides it into 3-hour blocks. Each block is evaluated against thresholds for the chosen surface type:

• Temperature — minimum temperature for paint drying (typically +5–10 °C)
• Humidity — maximum humidity (typically 80%)
• Wind — maximum wind speed, varying by paint type
• Rain — rain-free time required for painting and drying

Each block receives an assessment: suitable for painting, requires caution, or not suitable for painting. The evaluation uses worst-case aggregation — if any metric exceeds its threshold, the entire block receives a warning.

Threshold basis

Surface-specific thresholds (wood, concrete, metal, brick, etc.) are derived from paint manufacturer technical data sheets. Thresholds are conservative — they favour caution because weather forecasts always contain uncertainty.

Thresholds are hardcoded in the application (not in the database) to ensure fast evaluation without database queries. Product-specific data is separate and serves as reference information.

Maintenance

The service is maintained by JPSTech Solutions (business ID 2317443-3). Weather data updates automatically from the weather services. Product data and thresholds are reviewed manually.

The service follows the spirit of open source — transparency and reliability come first.