When is data valid, and how are accumulated values computed?

Unless otherwise stated in the documentation, a value is always valid at the timestamp of the data. That is, it is an instantaneous value.

For example (Hourly data):

{
      "precip": 5,
      "temp": 21,
      "timestamp_local": "2026-06-02T11:00:00",
      "timestamp_utc": "2026-06-02T18:00:00"
}

"temp": 21 -> 21 degrees Celsius AT "2026-06-02T11:00:00" local time.

"precip": 5 -> 5 mm of accumulated precipitation FROM the valid time "2026-06-02T10:00:00" TO the end of the hour time "2026-06-02T10:59:59".

The same extends to daily data.

{
    "precip": 15
    "temp": 20.4,
    "max_temp": 30,
    "min_temp": 15,
    "valid_date": "2026-06-03"
}

"temp": 20.4 -> 20.4 degree Celsius average temperature for 2026-06-03 FROM "2026-06-03T00:00:00" TO "2026-06-03T23:59:59" local time.

"precip": 15 -> 15 mm of accumulated precipitation FROM "2026-06-03T00:00:00" TO "2026-06-03T23:59:59" local time.

"max_temp": 30 degree Celsius max temp computed FROM "2026-06-03T00:00:00" TO "2026-06-03T23:59:59" local time.

Finally, for subhourly (15 minute) data - everything is instantaneous.

{
    "precip_rate": 3,
    "snow_rate": 0,
    "temp": 24.4,
    "timestamp_local": "2026-05-26T20:15:00",
    "timestamp_utc": "2026-05-27T00:15:00",
}

"temp": 24.4 -> 24.4 degree Celsius AT "2026-05-26T20:15:00" local time.

"precip_rate": 3 -> 3 mm/hour precipitation rate AT "2026-05-26T20:15:00" local time.