About PastWeather

Data Sources

PastWeather aggregates historical weather data from multiple reputable open-source archives and APIs to ensure accuracy and reliability. Our primary data providers include:

• Meteostat: A leading provider of historical weather and climate data, aggregating records from thousands of weather stations worldwide.
• Open-Meteo: Provides high-resolution historical weather data based on reanalysis models, filling gaps where station data might be sparse.

Methodology

We do not generate forecasts. Instead, we query historical archives to retrieve what actually happened on specific dates. When you search for a location, we:

1. Geocode your city to precise coordinates.
2. Query our providers for daily records (temperature, precipitation, wind, etc.) for your selected date range.
3. Cache the results to improve performance and reduce load on upstream APIs.

Data quality & transparency

• Per-metric source labeling (Meteostat / Open-Meteo) and coverage warnings when station data is sparse.
• Cache age and last refresh surfaced beside results so you know when data was last synced.
• Gap detection across date windows with clear “missing days” callouts and retry guidance.

Trust & safety

• Privacy-respecting analytics with no third-party cookies and an upcoming opt-in toggle.
• Abuse safeguards for rate limits and bot bursts without degrading a normal user experience.
• Clear feedback and takedown channel so issues reach an operator quickly.

Admin & ops

• Observability hooks for latency/error hotspots across providers and cache hits.
• Feature flags to safely roll out new chart types, metrics, and data providers.
• Status and health checks to surface upstream outages early and keep users informed.

Accessibility & localization

• Full keyboard navigation, visible focus rings, and ARIA labels across search, charts, and tables.
• Screen reader friendly summaries for charts/tables plus locale-aware dates, numbers, and timezones.
• Language toggle persistence, RTL readiness, and improved contrast modes for low-vision users.

Export & share

• One-click CSV and PNG export for charts and tables.
• Shareable permalinks that preserve location, date windows, and metric selections.
• Embeddable mini cards for blogs or research pages with attribution baked in.

Deeper insights

• Anomaly callouts versus normals and percentile bands on charts.
• Multi-day narratives for storms, heatwaves, and cold snaps stitched across ranges.
• Contextual climate notes that highlight records, extremes, and typical patterns.

Better discovery

• Map-based city picker with nearby suggestions and station density hints.
• “Nearby historical events” surfacing notable days close to your query.
• Popular and saved locations surfaced for quick recall across sessions.