Report updated Jun 1, 2026
Heat Index: Wet Bulb
For outdoor workers, athletes, and safety-conscious individuals who require accurate heat-related health data for planning activities.
Heat Index: Wet Bulb is an established weather app that is a paid app.
What is Heat Index: Wet Bulb?
Heat Index: Wet Bulb is a paid weather utility for iOS that provides heat index and WBGT safety metrics for outdoor planning.
Users hire this app to mitigate heat-related health risks through professional-grade guidance that general-purpose weather apps lack.
Current Momentum
v1.0 · 3mo ago
Maintenance- Launched initial iOS version February 2026.
Active Nemesis
Windy.com
By Windyty, SE
Other Rivals
7-Day Rank Pulse 🇺🇸
WeatherRating Pulse 🇺🇸
Gathering signals...
What makes this app unique?
How Is The App's Momentum Right Now?
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What Are The Key Features?
Displays current heat index and risk levels based on OSHA/NIOSH-style scales
Provides at-a-glance access to heat index and wet bulb data directly from the iOS home screen
Visualizes hourly trends and weekly outlooks for outdoor planning
Delivers weather data and forecasts without third-party advertisements
How much does it cost?
- $3.99 one-time purchase for full feature access
The app utilizes a buy-once model at $3.99, positioning itself as a privacy-focused, ad-free alternative to subscription or ad-supported weather services.
Who Built It?
What other apps does Mustafa Kulac make?
What do users think recently?
Analysis in progress, available soon
What is the competitive landscape for Heat Index: Wet Bulb?
How's The Weather Market?
How does it evolve in the Weather market?
The app holds the #70 Paid position in the US Weather category, signaling a niche but stable user base. The $3.99 price point creates a barrier to entry that limits discovery compared to free, ad-supported weather utilities.
| Country | Category | Chart | Rank | Change |
|---|---|---|---|---|
| 🇺🇸 US | Weather | iOSPaid | #75 | ▼14 |
The rivals identified
The Nemesis
- -
Provides professional-grade meteorological data layers including complex wind, pressure, and humidity visualization tools.
- -
Maintains a high-velocity release cadence with eight updates in the last six months alone.
Contenders
Windy.app — Wind, Tides, Radar
★4.7 (72.4K)Windy Weather World Inc
Directly targets the outdoor enthusiast niche with specialized weather metrics that overlap with wet bulb and heat index utility.
Offers specialized weather forecasting modules specifically tailored for water sports, sailing, and outdoor activity planning.
Integrates hyper-local tide and wind data that complements the target app's focus on heat-related safety.
Tomorrow.io: Weather Forecast
★4.6 (27.8K)The Tomorrow Companies, Inc
💀Positions itself as a hyper-local, actionable weather intelligence platform for safety-conscious users.
Focuses on hyper-local, minute-by-minute precipitation and weather alerts rather than general meteorological trends.
Provides actionable safety insights that mirror the target app's goal of preventing heat-related illness.
Peers
Offers a comprehensive, all-in-one weather suite that includes live radar, pollen counts, and long-term forecasts.
Leverages a massive, established user base to maintain high visibility in the general weather category.
Specializes in global air quality monitoring and health guidance, creating a strong parallel to heat-safety utility.
Provides community-driven data and health recommendations that build high user trust and retention.
RainViewer: Live Weather Radar
★4.6 (30.3K)MeteoLab Inc.
⚡Provides high-fidelity visual radar data that competes for screen time with the target app's widgets.
Delivers highly responsive, real-time radar animations that set the standard for visual weather tracking.
Maintains an aggressive update schedule to ensure compatibility with the latest iOS widget and live activity features.
Tides Near Me
★4.8 (155.5K)Shelter Island Mapping Company, LLC
⚡A niche utility app that demonstrates the success of a single-purpose, high-utility tool.
Focuses exclusively on tide and current data, proving the viability of specialized, non-generalist weather tools.
Maintains high user satisfaction through consistent, reliable updates and a focused feature set.
New Kids on the Block
Weather mini - Trip Forecasts
★4.7 (212.1K)Kai Luo
⚡Shows extreme development velocity with 25 releases in the last six months, signaling rapid iteration.
Prioritizes lightweight, trip-specific forecasting that minimizes data bloat for travelers on the move.
Rapidly iterating on user feedback to refine the UI for quick, at-a-glance weather checks.
The outtake for Heat Index: Wet Bulb
Strengths to defend, gaps to attack
Core Strengths
- Ad-free model removes user-experience friction
- OSHA-aligned risk guidance provides professional-grade safety utility
- One-time purchase model appeals to privacy-conscious users
Critical Frictions
- $3.99 entry barrier restricts top-of-funnel conversion
- Lack of free trial prevents user-intent testing
- No Android presence limits total addressable market
Growth Levers
- B2B partnerships with safety teams for bulk licensing
- Wearable integration for real-time alerts during outdoor work
Market Threats
- Subscription-based weather apps bundling WBGT data
- Free general-purpose apps adding specialized health metrics
- Rapid iteration from new entrants like Weather mini
What are the next best moves?
Ship a free-to-paid trial gate because the $3.99 barrier limits discovery → increase conversion velocity
The current paid-upfront model creates a high discovery barrier against free, ad-supported competitors.
Trade-off: Pause the development of the 7-day outlook expansion to prioritize the trial gate.
Build a watchOS companion app because outdoor workers require hands-free safety alerts → increase daily active usage
Target audience (outdoor workers) needs real-time safety data without manual phone checks.
Trade-off: Deprioritize the 48-hour trend chart refinement to allocate engineering hours to watchOS.
A counter-intuitive read
The app's lack of a free version is not a weakness but a moat: it filters for high-intent safety users who value privacy over the data-harvesting models of free weather apps.
Feature Gaps vs Competitors
- Real-time radar layers (available in Windy.com but absent here)
- Hyper-local minute-by-minute alerts (available in Tomorrow.io but absent here)
Key Takeaways
Heat Index: Wet Bulb secures a defensible niche through specialized safety metrics, but the paid-upfront model limits its reach against free alternatives, so the PM should prioritize a free-to-paid trial gate to lower the discovery barrier.
Where Is It Heading?
Stable
The weather utility market is consolidating around hyper-local, actionable safety data, putting pressure on static forecasting tools. Heat Index: Wet Bulb must shift from a static utility to a proactive alert system to maintain its relevance against subscription-based rivals.
The app maintains a steady niche position, but the lack of recent feature updates leaves it vulnerable to faster-moving competitors.
The $3.99 price point without a trial creates a conversion bottleneck that prevents the app from scaling beyond early adopters.