Local weather and seasonal temperatures

Current weather and seasonal averages answer different questions

Bilby shows weather as local context on plot, municipality and project surfaces where available. Current temperature and upcoming days come from SMHI point forecasts. Seasonal high/low averages come from historical observations at a qualifying nearby station. Neither is a weather, climate-suitability or house-matching score.

Sources, dates and geography

A plot uses its coordinates. A municipality page uses its representative weather location, not a spatial average across the municipality. The source update time belongs to the forecast, while seasonal values use 1991–2020 observations.

Current and upcoming weather

Bilby selects the first valid forecast point at or after the current time; if none remains, the parser falls back to the first valid point and the source timestamp helps identify stale data. “Today” and the next days are grouped in Europe/Stockholm time. Daily low/high are the minimum and maximum of available forecast temperatures for that day, rounded to whole degrees. The representative daily symbol is the point closest to noon. Up to five future days are shown. These sampled forecast extrema are not observations of the day’s actual extremes.

How the seasonal station means are made

The station must appear in both SMHI daily-minimum and daily-maximum station lists and cover the 1991–2020 period. Bilby chooses the geographically nearest qualifying candidate, loads its corrected archive, and requires at least 1,000 valid observations for every season in both series. If that candidate’s archive is insufficient, seasonal data is unavailable; the current path does not keep trying increasingly distant stations.

Winter groups December–February, spring March–May, summer June–August and autumn September–November. All usable daily highs in a season are averaged; daily lows are averaged separately. Results round to 0.1°C before presentation. This is a mean of available days, not an average of equally weighted years, record extremes or a municipality-wide climate normal.

Fictional aggregation

For a miniature illustration of the mean, daily summer highs 20, 22 and 24°C average 22.0°C, while lows 10, 12 and 14°C average 12.0°C. Three days alone would fail the production coverage requirement; the arithmetic does not waive the 1,000-observation gate. In a fictional forecast day with available points 8.4, 12.2 and 9.6°C, the displayed daily low/high are 8°C and 12°C. A noon point can supply the day’s icon without changing those extrema.

A nearby station is still another place

Station elevation, coast/inland exposure, shade and urban surroundings can differ from the plot. Missing days are not filled with zero. The period label stays 1991–2020 even when the website is viewed in a later year. Current forecasts may fail independently of historical data, so one can be present without the other. A forecast older than three hours is flagged stale in the context response. These values do not automatically reprice foundations, heating systems or the budget.

Method and review

The SMHI forecast/station collection, calculation and context cards were reviewed 18 October 2026. This review date does not replace the observation period or forecast update time. The seasonal card identifies the station and explains that Bilby calculated its averages. SMHI observations SMHI open data