How to Change Temperature and Measurement Units in the Weather App on iPhone

The native Weather app on iPhone provides detailed, hyper-local meteorological forecasts, precipitation graphs, wind vectors, atmospheric pressure readings, and ultraviolet (UV) index metrics. By default, iOS assigns measurement units based on the regional locale set in your device’s language and region settings. For example, devices configured for the United States default to Fahrenheit and miles per hour, whereas devices configured for the United Kingdom or Europe often default to Celsius and kilometres per hour.

However, many users prefer a hybrid setup—such as tracking temperature in Celsius while measuring wind speed in miles per hour, or monitoring barometric pressure in millibars rather than inches of mercury. Modern versions of iOS allow you to custom-configure every individual measurement metric directly inside the Weather app without having to change your overall iPhone region or system language.

Customisable Weather Metrics in iOS

Rather than enforcing an all-or-nothing imperial or metric switch, Apple’s Weather app divides meteorological metrics into five independent measurement categories:

• Temperature: Celsius (°C) or Fahrenheit (°F).
• Wind: Miles per hour (mph), Kilometres per hour (km/h), Metres per second (m/s), Knots (kn), or Beaufort scale.
• Precipitation: Millimetres (mm) or Inches (in).
• Pressure: Hectopascals/Millibars (hPa / mbar), Inches of mercury (inHg), Millimetres of mercury (mmHg), or Standard atmospheres (atm).
• Distance: Kilometres (km) or Miles (mi) for measuring visibility and radar map horizons.

How to Change Temperature Units Directly in the Weather App

If you only need to switch the baseline temperature between Celsius and Fahrenheit, you can toggle it in seconds from the Weather city list:

1. Open the Weather app on your iPhone.
2. If you are viewing a specific city forecast, tap the List icon (three horizontal lines and dots) in the bottom-right corner of the screen to view your saved locations.
3. Tap the More button (the three horizontal dots ... in a circle) located in the upper-right corner of the city list view.
4. At the bottom of the pop-up menu, you will see a direct toggle between Celsius and Fahrenheit:
   • Tap Celsius (°C) to convert all current temperatures, 10-day forecasts, and hourly charts to metric.
   • Tap Fahrenheit (°F) to switch all readings to imperial.

Every saved city card and lock screen weather widget updates immediately to display your chosen temperature scale.

How to Fine-Tune Individual Measurement Units (Wind, Pressure, Distance)

To configure advanced meteorological metrics independently of your primary temperature scale:

1. In the Weather app, ensure you are on the city list view (tap the list icon in the lower-right if necessary).
2. Tap the three dots (...) in the top-right corner.
3. Select Units from the menu.
4. You will be presented with the dedicated Units configuration screen:
   • Temperature: Select your preference (°C or °F).
   • Wind: Tap to select between Kilometres Per Hour (km/h), Miles Per Hour (mph), Metres Per Second (m/s), or Knots (kn). (Knots is especially popular for sailing and coastal watersports).
   • Precipitation: Choose between Millimetres (mm) and Inches (in) for rainfall tracking.
   • Distance: Select Kilometres (km) or Miles (mi) for atmospheric visibility.
   • Pressure: Select Millibars (mbar / hPa), Inches of Mercury (inHg), or Millimetres of Mercury (mmHg).
5. Once you have adjusted each category to your preferred specification, tap Done in the top-right corner.

The app immediately recalculates and formats the entire data card grid, allowing you to review radar maps and wind compasses in your exact technical standard.

How to Restore Regional Default Weather Units

If you have customized multiple metrics and want to return to the official standard used by your device’s geographical region:

1. Open the Weather app and tap the list icon.
2. Tap the three dots (...) and select Units.
3. Scroll to the very bottom of the Units menu.
4. Tap Restore Defaults.
5. Tap Done.

The Weather app will immediately re-align with your iPhone’s system-level regional preferences located in Settings > General > Language & Region.

Syncing Custom Weather Units with Apple Watch and iPad

Because your Apple Watch and iPad typically mirror weather settings from your paired iPhone, changes made in iOS will sync across iCloud. If your Apple Watch continues to show the old measurement units after making changes on your iPhone:

1. Open the Watch app on your iPhone.
2. Scroll down and tap Weather.
3. Ensure Mirror my iPhone is selected under the Weather notification and display preferences.

Within a few moments, complications, Smart Stack widgets, and full watchOS Weather app views will display in your custom units seamlessly.