Ue Udw Random Seasons Temperature

UDW random weather, seasons, climate, temperature

The systems that make weather feel naturally varied over time: random variation, seasonal cycles, climate-aware probability, and the temperature system that derives values from all of it.

When to use this skill

• Setting up weather that changes by itself periodically.
• Making weather change with seasons.
• Picking a real-world climate (tropical, alpine, desert) for a region.
• Reading temperature in F or C from gameplay code.
• Adding local hot zones (near fire) or cold zones.
• Displaying current temperature on screen.
• Driving materials based on the season.

Random Weather Variation

Periodically picks a new weather preset based on season and probability maps. Category: Random Weather Variation.

Timing modes

Transition Length — fraction of the interval between changes devoted to transitioning old → new.

Probability maps

The Weather Type Probabilities maps hold weather presets and their relative probabilities. Values are relative:

{ Rain: 5, Partly Cloudy: 1, Clear: 1 }
   → Rain is 5x as likely as either of the others

Which map is used depends on the current season (see below). Different probability maps per season is how spring rains differ from summer heat.

Begin Play behavior

Climate Presets

Same category — apply a climate preset to populate the probability maps with real-world climate data, and set temperature ranges in the Temperature category accordingly. Fastest way to get believable weather for "tropical jungle", "alpine", "desert", etc.

Returning to random after a manual change

Change Weather (see ue-udw-setup-and-state) switches to a static preset. To go back:

UDW.ChangeToRandomWeatherVariation()

Seasons

Category: Season. The Season variable is a float 0–4:

Whole values = middle of a season (where its data is applied purely). In-between values = transition. 0.5 = half Spring + half Summer.

Where Season comes from

When deriving from date:

Sampling season in materials

Use for season-driven material effects (autumn foliage colors, winter rock tinting).

Temperature

Category: Temperature. Sample via:

UDW.GetCurrentTemperature(unit, sampleLocation)
// unit: Fahrenheit or Celsius
// sampleLocation: Global, or per-location (volumes + interior)

How temperature is calculated

Treated as a product of weather, not a driver of it:

1. Start at 0
2. Add every Temperature Bias value in the Temperature category
   (biases reflect factors like Time of Day and weather state)
3. Map the resulting -1..1 value into the Min/Max range for current season
4. Add a slowly-changing random value, scaled by Randomize Temperature
5. If sampleLocation != Global:
   - Sample Temperature Volumes in the level
   - Apply Interior Temperature based on Player Occlusion of the sample point
     (Player Occlusion is on UDS — see ue-uds-modifiers-configs-state)

Temperature and Weather Override Volumes

Weather Override Volumes apply their own temperature ranges while the player is inside. Configurable per-WOV or disablable. See ue-udw-spatial-weather.

Temperature Volumes

Actor class Temperature Volume at Blueprints/Weather_Effects/. Place to create local temperature effects.

Example: place around a fire with a positive Temperature Offset — temperature sampled inside the volume reads higher.

Show temperature on-screen

UDW Thermometer widget in the widget designer palette under Ultra Dynamic Sky Widgets. Samples and displays current temperature. Drop into a UMG widget.

Runtime / Blueprint scripting summary

Gotchas

• Random Weather Variation doesn't fire — mode is set to something other than Random Interval / Daily / Hourly. Pick a timing mode.
• Begin Play weather isn't random — Begin Play Weather is Random is false. Set it true.
• Random weather always picks the same preset — probability map has a strong bias toward one entry; or there's only one entry in the map. Verify the map for the current season.
• SetSeason has no effect — Season Mode is set to derive from date, which overrides manual season. Switch Season Mode to "Uncontrolled" first.
• Temperature reads always the same despite weather changing — Temperature Bias values aren't configured for the weather you care about. Add bias entries for that weather/time-of-day.
• GetCurrentTemperature(local) reads same as Global — sample location is set to Global, or there are no Temperature Volumes / Player Occlusion isn't computing occlusion at that location. See ue-uds-modifiers-configs-state.
• Climate preset overwrote a custom probability map — applying a climate preset is destructive to the maps. Save a config asset first (see ue-uds-modifiers-configs-state) before experimenting.

References & source material

Docs (Ultra Dynamic Weather 9.5):

• Random Weather Variation
• Seasons
• Sampling Temperature (incl. how temperature is calculated, Temperature Volumes, on-screen display)

Plugin asset paths:

• Blueprints/Weather_Effects/Weather_Presets/ — preset assets weighted by the probability maps
• Blueprints/Weather_Effects/ — Temperature Volume actor class
• Widget designer palette → Ultra Dynamic Sky Widgets → UDW Thermometer

Related skills: ue-udw-setup-and-state, ue-uds-simulation (date drives season when Season Mode set to derive), ue-udw-spatial-weather (WOVs override temperature ranges locally), ue-uds-modifiers-configs-state (Player Occlusion drives Interior Temperature), ue-udw-material-and-screen-effects (Freezing Breath uses calculated temperature).