Weather¶

Particle Man creates a native Home Assistant weather entity using the Google Weather API, along with several extra sensors for data that doesn't fit the standard weather card.

The Weather Entity¶

The weather entity appears as Particle Man Weather in your weather cards and automations. It works with all native HA weather cards and supports the weather.get_forecasts action.

Current Conditions¶

Property	Source
Condition	Mapped from Google's weather condition type
Temperature	Current air temperature
Feels Like	Apparent temperature accounting for humidity and wind
Dew Point	Temperature at which air becomes saturated
Humidity	Relative humidity (%)
Wind Speed	Speed at standard anemometer height
Wind Direction	Bearing in degrees
Wind Gust	Maximum gust speed
Pressure	Mean sea level pressure (hPa)
Visibility	Horizontal visibility distance
UV Index	Current UV index
Cloud Cover	Percentage of sky covered by clouds
Ozone	Ozone concentration in ppb (from Air Quality API; `None` when Air Quality is disabled)

Forecast Types¶

The entity exposes three forecast types accessible via weather.get_forecasts:

Type	Coverage	Entries
`hourly`	Configurable — 24, 48, 72, 120 (default) or 240 hours	One entry per hour
`daily`	Next 5 days	5 entries, daytime conditions
`twice_daily`	Next 5 days	10 entries (day + night per day)

Hourly forecast length is set in Configure → Weather Options. Google returns at most 24 hours per API call, so each additional 24 hours costs one more call per refresh — the option lists the cost of each choice. Longer forecasts are automatically refreshed less often to stay inside your monthly limit.

Each forecast entry includes: condition, temperature, apparent temperature, precipitation probability, precipitation amount, wind speed/bearing/gust, humidity, pressure, cloud coverage, and UV index. Daily and twice-daily entries also include a low temperature. Daily precipitation is the 24-hour total (daytime + overnight). Hourly entries additionally include dew point. Hourly entries are always filtered to start at the current hour — past hours are automatically excluded, so the list stays current even if data was fetched before quiet hours started.

Condition Mapping¶

Google's weather conditions are mapped to Home Assistant standard conditions. (Google weather condition types)

Google Condition	HA Condition
CLEAR (daytime)	sunny
CLEAR (nighttime)	clear-night
MOSTLY_CLEAR, PARTLY_CLOUDY	partlycloudy
MOSTLY_CLOUDY, CLOUDY, OVERCAST	cloudy
DRIZZLE, LIGHT_RAIN, RAIN, RAIN_SHOWERS	rainy
HEAVY_RAIN, HEAVY_RAIN_SHOWERS	pouring
THUNDERSTORM, THUNDERSTORM_WITH_RAIN, SCATTERED_THUNDERSTORMS	lightning-rainy
LIGHTNING	lightning
LIGHT_SNOW, SNOW, HEAVY_SNOW, SNOW_SHOWERS, BLIZZARD	snowy
SLEET, HAIL, FREEZING_RAIN, FREEZING_DRIZZLE, ICE_PELLETS, WINTRY_MIX	hail
FOG, HAZE, SMOKE	fog
WINDY, BREEZY	windy
DUST, SAND, TORNADO, HURRICANE, TROPICAL_STORM	exceptional

Extra Weather Sensors¶

These sensors expose weather data that doesn't fit into the standard WeatherEntity schema.

Thunderstorm Probability (%)¶

The probability of a thunderstorm occurring in the current hour. Useful for automations that need to respond before a storm arrives rather than after conditions worsen.

Heat Index (°)¶

The "feels like" temperature accounting for high humidity in warm conditions. Only meaningful when temperature and humidity are both elevated; Google returns null otherwise.

Wind Chill (°)¶

The "feels like" temperature accounting for wind in cold conditions. Only meaningful in cold weather; Google returns null otherwise.

UV Index Category¶

The current UV index expressed as a plain-language WHO category: Low, Moderate, High, Very High, or Extreme. The raw UV index value is available as the uv_index attribute. The numeric UV index is also available directly on the weather entity.

Weather Alert Sensors¶

When weather alerts are enabled (Configure → Weather Options), Particle Man creates three sensors:

Alert Count¶

State: The integer count of currently active warnings (0 = no alerts).

Attributes:

Attribute	Description
`alerts`	Full list of active alerts — each entry includes title, severity, event type, area, start/expiration time, description, and instructions
`highest_severity`	Worst severity among active alerts: `MINOR`, `MODERATE`, `SEVERE`, or `EXTREME`
`active_event_types`	Sorted unique list of active event type codes (e.g. `FLOOD_WATCH`, `TORNADO_WARNING`)

Alert Highest Severity¶

State: The worst severity level across all active alerts: MINOR, MODERATE, SEVERE, or EXTREME. None when no alerts are active.

Use directly in automations to trigger on severity level without reading attributes.

Alert Event Types¶

State: Comma-separated sorted list of active alert type codes, e.g. FLOOD_WATCH, TORNADO_WARNING. None when no alerts are active.

Note

Weather alerts are only available in regions covered by Google's public alerts service, primarily the US and some international regions. (Weather API coverage)

A count of 0 with None severity and event types means no alerts are currently active — the sensors are working normally.

Units¶

The weather entity and extra sensors use the units selected in Configure → Weather Options:

Setting	Temperature	Wind	Precipitation	Visibility
Metric	°C	km/h	mm	km
Imperial	°F	mph	in	mi

Home Assistant can convert between units for display purposes independently of the units stored in the sensor.

Minute Forecast (Nowcast)¶

Experimental

Google classifies the minute forecast as Experimental (pre-GA) — its lowest stability tier. It is absent from the REST reference, the coverage table and the pricing list, so its availability and billing are both undocumented. Particle Man therefore treats it as billed and leaves it off by default. Field names may change without notice.

Enable it in Configure → Weather Options. It adds a six-hour precipitation nowcast refreshed every 15 minutes, at a cost of roughly 2,200 calls per month per location — about a quarter of the free tier.

Coverage appears limited to the US and Europe. Where Google has no nowcast for your location the API returns an error; Particle Man disables the feature for that location and raises a repair notice rather than retrying. It re-arms on the next reload, so a later Google rollout is picked up automatically. No other weather data is affected.

Nowcast sensors¶

Sensor	State
Minutes Until Precipitation	Minutes until precipitation begins; `0` while it is falling; unknown if none is expected in the window
Precipitation Ends In	Minutes until the current precipitation stops; unknown when nothing is falling
Precipitation Intensity	`NO_INTENSITY`, `LIGHT`, `MODERATE` or `HEAVY` right now
Precipitation Type	`RAIN`, `SNOW`, `HAIL` or `NONE` right now — the only place hail surfaces distinctly

These update every minute, independently of the API refresh, so the countdown is always current rather than jumping once per refresh cycle.

Minutes Until Precipitation attributes:

Attribute	Description
`is_precipitating`	Whether precipitation is falling now
`starts_at` / `ends_at`	Bounds of the relevant precipitation run
`type` / `types`	Type of the run; `types` lists every type if it changes mid-run (e.g. rain turning to snow)
`max_intensity` / `max_probability`	Worst intensity and highest probability across the run
`runs`	Every distinct precipitation block in the window — usually 0–3
`segments`	The full normalized segment list
`horizon_start` / `horizon_end`	Bounds of the forecast window
`stale`	True once the window has elapsed

A segment counts as precipitation only when its type is not NONE, its intensity is not NO_INTENSITY, and its probability is at least 50% — without that threshold the sensor would read "raining" almost permanently in a drizzly climate.

`get_minute_forecast` action¶

The weather entity exposes particle_man.get_minute_forecast, returning the next hour in the same shape as Home Assistant's OpenWeatherMap integration, so nowcast-capable dashboard cards work against it:

action: particle_man.get_minute_forecast
target:
  entity_id: weather.home_weather

{
  "weather.home_weather": {
    "forecast": [
      {
        "datetime": "2026-08-12T14:22:00+00:00",
        "precipitation": 6.0,
        "type": "RAIN",
        "probability": 82,
        "intensity": "LIGHT",
        "end": "2026-08-12T14:24:00+00:00"
      }
    ]
  }
}

precipitation is a rate in mm/h. Dry stretches report 0 rather than being omitted, so consumers draw a dry spell instead of a gap.

Forecast Sensors¶

Home Assistant removed the forecast attribute from weather entities in 2024.4, so templates can no longer read forecasts directly from weather.*. Particle Man provides Hourly Forecast and Daily Forecast sensors whose forecast attribute holds the full list, matching how the air quality and pollen sensors already work.

Both are disabled by default — enable them in the entity settings if you template against forecast data. The arrays are excluded from the recorder, so they cost nothing to store no matter how long your history retention is.

API Calls¶

Weather data comes from up to five Google Weather API endpoints, each refreshing on its own cadence rather than all together:

Endpoint	Purpose	Default cadence
`GET /currentConditions`	Current state, extra sensors	15 min
`GET /forecast/hours`	Hourly forecast	60 min
`GET /forecast/days`	Daily + twice-daily forecast	180 min
`GET /publicAlerts`	Active weather alerts (if enabled)	30 min
`GET /forecast/minutes`	Precipitation nowcast (if enabled)	15 min

At one location with default settings that projects to about 6,324 calls per month against Google's 10,000 free tier — or 8,556 with minutecast enabled. See Reference — How data updates for the full budget model.