weatherapi/docs/roadmap/current.md

Current Conditions Condition-Code Selection

Summary

Improve /conditions/current so numeric conditions continue to aggregate from recent observations, but conditionCode is selected by source-balanced WMO family consensus instead of numeric maximum. The goal is to prevent a single bad high WMO code, such as an erroneous thunderstorm code, from dominating current conditions while still returning a useful code when providers report semantically similar conditions.

Target Behavior

Current conditions continue to use the application observation window, currently app.ObservationWindowMinutesDefault.

Numeric and directional fields remain aggregate values over recent observations rows:

• temperature, apparent temperature, dewpoint, relative humidity, and wind speed use averages;
• wind direction uses circular averaging;
• isDay comes from the latest row in the window.

conditionCode uses source-balanced consensus:

1. Select the latest observation per event_source within the current window.
2. Each source contributes at most one WMO condition-code vote.
3. Map each voted WMO code to a semantic family.
4. Select the family with the highest source vote count.
5. If the family vote is tied, return model.WMOUnknown.
6. Within the winning family, select the most frequent exact WMO code.
7. If exact-code vote is tied within the winning family, select the first code by family-specific representative ranking.
8. If there are no recognized condition-code votes, return model.WMOUnknown.

Family mapping and tie ranking:

Family	Codes / tie ranking
clear_or_cloud	0, 1, 2, 3
fog	45, 48
drizzle	51, 53, 55, 56, 57
rain	61, 63, 65, 80, 81, 82, 66, 67
snow	71, 73, 75, 85, 86, 77
thunderstorm	95, 96, 99

Examples:

Source votes	Result
0, 1, 2	0
1, 2, 95	1
0, 95	model.WMOUnknown
61, 63, 80	61
61, 95, 0	model.WMOUnknown
only 95	95

Policy Decisions

• No public response schema change is required.
• No weatherfeeder change or database migration is required because observations.event_source, condition_code, observed_at, and event_emitted_at already exist.
• Provider-specific blacklists, trust weights, and source priorities are intentionally out of scope for this change.
• WMOUnknown is preferable to falsely choosing between tied precipitation, thunderstorm, and clear/cloud families.
• Current conditions remain a latest-window read model, not a durable derived table.