Getting Started with Zeph
What is Zeph and how does it help outdoor athletes?
Zeph is an AI-powered weather app that analyzes outdoor conditions to find your ideal workout window. Instead of checking multiple weather apps and guessing when to exercise, Zeph provides a clear recommendation based on temperature, humidity, UV index, wind speed, and precipitation—all customized for your specific activity type (running, cycling, walking, or HIIT) and personal preferences. It's designed specifically for outdoor fitness enthusiasts who want to train smart and optimize their performance based on weather conditions.
How does the Zeph weather scoring system work for workouts?
Zeph calculates a workout readiness score from 1-10 for each hour of the day based on five critical weather factors:
- Temperature (60%) - Compares the "feels like" temperature to your ideal range for the selected activity. Running performs best at 45-65°F, while HIIT needs 50-68°F
- Humidity (15%) - Lower humidity means easier breathing, better sweat evaporation, and more efficient cooling during outdoor exercise
- UV Index (12%) - Evaluates sun exposure risk and sun protection requirements for safe outdoor training
- Wind (8%) - Assesses cooling effect or resistance, particularly important for cycling where headwinds significantly impact performance
- Rain Probability (5%) - Considers chance of precipitation to help you avoid getting caught in bad weather
A score of 8-10 indicates ideal workout conditions, 5-7 suggests acceptable conditions with minor compromises, and 4 or below means you should consider indoor training options for optimal performance and safety.
How much does Zeph cost?
Zeph is available for $5.99/month or $49.99/year (save 17% with annual billing).
Your subscription includes:
- 5-day extended forecast with hourly workout scoring
- All 5 activity types (Running, Cycling, Walking, HIIT, General)
- Unlimited saved locations
- Smart notifications: morning briefings and window alerts
- Air Quality Index monitoring
- Priority access to new features
We offer a 7-day free trial so you can experience how Zeph transforms your outdoor workout planning before committing to a subscription.
Why Zeph vs. Alternatives
Can't I just check my weather app before running?
Sure—but then you're interpreting "73°F, 65% humidity, 12 mph wind" without knowing if that's actually good for a tempo run. Zeph does the calculation for you using research-backed thresholds for each activity type (running, cycling, HIIT, walking), saving you 5 minutes of mental math every morning. We weight temperature, humidity, UV, wind, and precipitation based on physiological impact—not just "feels like" temperature.
Doesn't Strava already show weather data?
Strava shows weather after your workout (for logging and activity context), not predictive recommendations. Zeph tells you when to go before you lace up, based on your specific activity's weather sensitivity. Think of it as the difference between a post-workout report card and a pre-workout coach giving you the optimal training time.
I've always just "winged it" with outdoor workouts—why change?
If you're training for something specific (race PR, consistency streak, injury recovery), conditions matter more than you think. Training in 85°F heat when 65°F was available 3 hours earlier isn't grit—it's just harder recovery and increased injury risk. Zeph helps you train smarter, not just harder. Over a training cycle, that compounds into better performance and fewer missed workouts due to heat exhaustion or weather-related setbacks.
How is Zeph different from other weather apps?
Generic weather apps give you data; Zeph gives you decisions. Instead of showing you hourly forecasts and leaving you to interpret them, we analyze 7 key metrics (temperature, humidity, wind speed, wind gusts, UV index, precipitation probability, and weather conditions) and distill them into one clear recommendation: your optimal workout window with a readiness score. We're built specifically for outdoor athletes who need actionable guidance, not meteorologists who want raw data.
Zeph Features & Capabilities
What workout activities does Zeph support?
Zeph currently supports five outdoor activity types, each with customized weather preferences and ideal temperature ranges:
- Running - Optimized for cooler temperatures (ideal: 45-65°F) with emphasis on humidity and sun exposure for distance runners
- Walking - More tolerant temperature range with evening-friendly scoring, perfect for daily outdoor walks and recovery
- Cycling - Wind-sensitive scoring system that factors in headwinds, crosswinds, and visibility considerations for road cyclists
- HIIT (High-Intensity Interval Training) - Requires cooler temps (50-68°F) due to intense exertion and heat generation during workouts
- General Outdoor Workout - Balanced scoring for mixed activities, outdoor bootcamps, and varied training sessions
Each activity type uses a tailored algorithm that weighs weather factors differently based on how they impact performance and comfort for that specific exercise.
Can I check workout weather for other locations?
Yes! Tap on the location name in the app to open the location picker. You can search for any city worldwide and save it for quick access. This feature is perfect for planning workouts when traveling, checking conditions at a nearby park or trail, or comparing weather across different locations. Zeph maintains your location preferences and provides the same detailed weather analysis for any saved location.
How far ahead can I see the workout weather forecast?
Zeph provides a 5-day weather forecast with hourly workout scoring and recommendations. Swipe through the day cards to view optimal workout windows for each upcoming day. This helps you plan your weekly training schedule around weather conditions. Keep in mind that weather forecasts become less accurate further out, so we recommend checking Zeph again on the actual day of your planned workout for the most precise timing recommendation.
Does Zeph show air quality for outdoor workouts?
Yes! Zeph displays the Air Quality Index (AQI) for your location because air quality significantly affects breathing, cardiovascular performance, and overall workout safety. Poor air quality can reduce athletic performance and pose health risks during intense exercise. If the AQI exceeds 100 (unhealthy for sensitive groups), you'll see a clear warning in the app. We recommend considering indoor workout options or significantly reducing workout intensity when air quality is poor, especially for cardio-intensive activities like running and HIIT.
Smart Workout Notifications
What notifications can I receive from Zeph?
Zeph offers two types of smart notifications to help you never miss your ideal workout window:
- Morning Briefing - A daily weather summary showing your best workout window for the day, delivered at your chosen time (great for planning your workout schedule)
- Window Alerts - A reminder notification sent before your optimal workout window starts. You can configure this for 15, 30, or 60 minutes before the ideal time, giving you enough notice to prepare
Both notification types are completely optional and can be customized or disabled based on your preferences.
How do I enable workout notifications in Zeph?
Tap the bell icon in the top-right corner of the main screen to access notification settings. You'll need to grant notification permissions to Zeph the first time (this is a standard iOS permission). From the notification settings screen, you can enable or disable each notification type independently and customize the timing for morning briefings and window alerts. You have complete control over when and how often Zeph sends you workout recommendations.
Privacy & Data Security
Does Zeph track my location?
Zeph only uses your location when you're actively using the app to fetch accurate weather data for your current area. We do not track your location in the background, store your location history, or monitor your movements. Your privacy is paramount—you can also manually search and enter any location if you prefer not to share your current GPS location with the app. All location data is used solely for providing you with relevant weather forecasts and workout recommendations.
Is my personal data sold or shared with third parties?
Absolutely not. Zeph does not sell or share your personal data with any third parties for advertising or marketing purposes. Your workout preferences, notification settings, and saved locations are stored locally on your device for optimal performance and privacy. We take your data privacy seriously and are committed to protecting your information. For complete details on how we handle data, please review our comprehensive Privacy Policy.