Observation schema

weather.observations() returns merged METAR/SPECI reports. The canonical schema.observation.merged.v1 record has 30 fields; the weather read also attaches local_standard_date, the local-standard-time day used by training and settlement joins.

Python DataFrames and TypeScript rows use snake_case. They are not yet byte-for-byte identical, so inspect the returned schema before sharing a frozen contract across runtimes.

Identity and time

Field	Type	Notes
`station`	string	Canonical ICAO/ASOS id, for example `KNYC`
`event_time_utc`	UTC timestamp string	When the report is valid
`observation_type`	enum	`METAR` or `SPECI`
`source`	string	Bare row source: `awc`, `iem`, or `ghcnh`
`local_standard_date`	date	Derived local-standard-time day for this station

The merged report key is (station, event_time_utc, observation_type). When sources overlap, the fixed merge priority selects one survivor and the row keeps the source that actually won.

Temperature

Field	Unit	Nullable
`temp_c`	°C	Yes
`temp_f`	°F	Yes
`dewpoint_c`	°C	Yes
`dewpoint_f`	°F	Yes

The SDK preserves the available precision. Integer settlement rounding belongs in the settlement recipe, not the stored observation.

Wind

Field	Unit	Nullable
`wind_direction_degrees`	degrees true	Yes
`wind_speed_kt`	knots	Yes
`wind_gust_kt`	knots	Yes

Variable winds can have a null direction.

Pressure, visibility, and precipitation

Field	Unit	Notes
`altimeter_inhg`	inHg	Altimeter setting
`sea_level_pressure_hpa`	hPa	Sea-level pressure
`visibility_miles`	statute miles	Parsed report visibility
`precipitation_in_1h`	inches	Accumulation in the preceding hour

These measurements are nullable when the source report does not carry them.

Sky layers

Up to four layers are preserved:

Fields	Notes
`sky_cover_1` … `sky_cover_4`	`CLR`, `FEW`, `SCT`, `BKN`, `OVC`, `VV`, or null
`sky_base_1_ft` … `sky_base_4_ft`	Layer base in feet, nullable

Layer 1 is the lowest reported significant layer.

Weather, peak wind, snow, and raw report

Field	Notes
`weather_codes`	Raw METAR weather-code string
`peak_wind_gust_kt`	Peak gust in knots
`peak_wind_direction_degrees`	Peak-wind direction
`peak_wind_time`	Peak-wind timestamp
`snow_depth_inches`	Snow depth
`qc_field`	Upstream source quality marker
`raw_metar`	Original METAR text when the source provides it

AWC’s structured JSON can leave raw_metar null. Do not assume every provider exposes the original bulletin text.

Field count

The 30 canonical merged-schema fields are:

identity/source: 4
temperature: 4
wind: 3
pressure/visibility/precipitation: 4
sky cover and bases: 8
weather/peak wind/snow/QC/raw text: 7

local_standard_date is the additional derived join column on weather.observations() output.

1.x to 2.0 name changes

Common stale names and their 2.0 replacements:

1.x or pre-contract name	2.0
`station_code`	`station`
`observed_at`	`event_time_utc`
`wind_dir_degrees`	`wind_direction_degrees`
`sea_level_pressure_mb`	`sea_level_pressure_hpa`
`precip_1hr_inches`	`precipitation_in_1h`
`peak_wind_dir`	`peak_wind_direction_degrees`

Weather observations for query examples
Sources & provenance for merge and source-pin behavior
Daily windows for local-day bucketing
Quality control for the optional obs_qc_status annotation