See how today really feels. Now optimized for iPhone Duo, with faster widgets, new Apple Watch complications, and improved CarPlay.
Most weather apps give you numbers. Thermo Diem gives you context.
A 72° day after freezing weather can feel completely different from 72° after a heat wave. Thermo Diem compares apparent temperature across time, giving you an immediate answer:
How does today feel compared with yesterday?
You can also look ahead to tomorrow and explore how upcoming days may feel relative to right now or yesterday’s high.
RELATIVE WEATHER AT A GLANCE
Thermo Diem translates complex weather data into seven clear shifts:
• Much Warmer
• Warmer
• A Little Warmer
• About the Same
• A Little Cooler
• Cooler
• Much Cooler
Color-synchronized spectrum gauges make every change easy to understand at a glance.
APPARENT TEMPERATURE, EXPLAINED
Air temperature is only part of how weather feels. Thermo Diem combines established biometeorological models—including NOAA Wind Chill, the Rothfusz Heat Index, and Steadman-based apparent-temperature calculations—to account for conditions such as:
• Humidity and vapor pressure
• Wind and convective heat loss
• Sunlight and solar exposure
• The combined thermal effect on the human body
The result is a more useful feels-like temperature, placed in the context of recent and upcoming conditions.
TREND CURVES & FUTURE SHIFT
See today’s feels-like trajectory alongside yesterday’s curve. Explore the seven-day forecast, select upcoming hours, and compare future conditions with right now, the same time yesterday, or yesterday’s high.
BUILT FOR IPHONE DUO
Open iPhone Duo to reveal a spacious paired comparison of reference and target conditions. Adaptive layouts support expanded, folded, and tabletop use while preserving your selected day, hour, and comparison.
CARPLAY, DYNAMIC ISLAND & LIVE ACTIVITIES
Bring relative-weather intelligence into your commute. Thermo Diem displays glanceable temperature shifts, feels-like conditions, and synchronized spectrum gauges across CarPlay, the Lock Screen, and Dynamic Island.
HOME & LOCK SCREEN WIDGETS
Bring Thermo Diem’s bold poster typography to your Home Screen and Lock Screen. Choose from headline, overview, gauge, commute, and driving-focused layouts. Widgets update throughout the day and can be customized with comparison targets and display options.
APPLE WATCH
Use the standalone Apple Watch app for fast, independent weather checks. A growing collection of complications supports Corner, Circular, Rectangular, and Inline layouts, with designs optimized for glanceability across different watch faces.
NATIONWIDE MOVERS
Discover where the country’s biggest temperature shifts are happening. Nationwide Movers highlights major 24-hour changes across diverse climate regions.
AVAILABLE IN 4 LANGUAGES
Thermo Diem supports English, Spanish, French, and German throughout the app, widgets, and Apple Watch experience.
PRIVACY FIRST
No advertising networks, behavioral tracking, or data harvesting. Just clear, focused weather intelligence.
Ratings & Reviews
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What’s New
• Native support for iPhone Duo, with adaptive layouts for expanded, folded, and tabletop use
• Refresh button added to widgets
• Faster, more reliable widget updates throughout the day and overnight.
• New Apple Watch complications and refreshed watch-face designs
• Improved CarPlay widgets and Live Activity presentation
• More consistent weather comparisons across iPhone, Apple Watch, widgets, and CarPlay
• Clearer handling when historical comparison data is unavailable
• Refined typography, layouts, localization, and accessibility
• Performance improvements and general optimizations
• Bug fixes and reliability improvements
Version 3.8
The developer, Basic Function, indicated that the app’s privacy practices may include handling of data as described below. For more information, see the developer’s privacy policy .
Data Not Linked to You
The following data may be collected but it is not linked to your identity:
Location
Privacy practices may vary based, for example, on the features you use or your age. Learn More
The developer indicated that this app supports the following accessibility features. Learn More
