WetBulbAlert – Humid Heat Warning

Wet-bulb temperature alerts and forecast for outdoor workers and heat-prone regions

Problem

The user notes that dry summer heat once peaked in May/June but now extends into September, with temperatures often reaching 37°C or even 43°C. Wet-bulb temperature is the real metric for human heat stress, but it's not available or easy to interpret in typical weather apps, which only show dry-bulb temperature.

Solution

Compute wet-bulb temperature from public weather data, provide a 24–72 hour forecast curve with risk levels, send push notifications before dangerous thresholds, and include actionable advice for outdoor activities (hydration, shade timing).

Users

Outdoor workers, athletes, caregivers of elderly, climate-concerned residents in hot regions

MVP

Fetch free weather API and compute wet-bulb; display current and 24h forecast curve; customizable threshold push notifications; simple activity advice text; no sign-up, local location storage

Revenue

Freemium with subscription ($2.99/mo) for multi-location monitoring, extended forecast, historical extreme reports; affiliate partnerships with outdoor gear brands

Why now

Extreme heat is becoming more frequent; wet-bulb concept entered public awareness via works like Ministry for the Future, but dedicated tools are scarce; indie developers can build fast with public weather data and no hardware.