Tempest Weather System Review

The WeatherFlow Tempest Weather System takes a fundamentally different approach to home weather monitoring. Where every other station in its class uses mechanical components, tipping-bucket rain gauges, and separate sensor arrays connected by cables, the Tempest packages everything into a single compact unit with zero moving parts. After eight months of continuous operation through Gulf Coast storms, we have a thorough understanding of what it does brilliantly and where it falls short.

What Makes the Tempest Different

The Tempest is a single cylindrical device, roughly the size of a coffee thermos, that sits atop a mounting pole. Inside that one unit is everything: an ultrasonic anemometer (wind), haptic rain sensor, temperature and humidity sensor, barometric pressure sensor, UV and solar radiation sensors, and a lightning strike detector. There are no external cables, no separate anemometer arm, and no tipping-bucket rain collector.

Power comes exclusively from a built-in solar panel and internal supercapacitor. There are no batteries to replace. The sensor communicates with a small indoor hub via Bluetooth Low Energy, and the hub connects to your Wi-Fi network to upload data to the WeatherFlow cloud.

This design philosophy results in a station that is genuinely maintenance-free. There is nothing to clean (no rain gauge funnel to unclog), nothing to replace (no anemometer bearings to wear out), and nothing to recharge. Mount it and forget it.

Specifications

Installation: Genuinely Simple

Installation takes about 20 minutes. The package includes the Tempest sensor, hub, mounting pole, and hardware. Screw the mounting pole onto any post or railing (or use a Davis tripod mount for a rooftop installation), slide the Tempest onto the pole, and it is physically done.

The hub plugs into any indoor outlet and pairs with the Tempest automatically. Download the Tempest app, create an account, connect the hub to Wi-Fi, and data starts flowing within 5 minutes. The entire process, from opening the box to seeing live data on your phone, took us 18 minutes.

Compare that to a Davis Vantage Pro2, which requires assembling a multi-piece sensor suite, running cables between the anemometer and ISS, mounting everything on a pole, aligning the wind vane, and configuring a separate internet hub. The Tempest's simplicity is its most underrated feature.

Wind Measurement: Excellent

The ultrasonic anemometer is the Tempest's strongest sensor. It uses four transducers to measure both wind speed and direction simultaneously, with no startup threshold and no moving parts to degrade. In our testing against a calibrated reference anemometer, the Tempest tracked within 1 mph across all wind speeds from calm to 50 mph.

The 3-second update interval means you see gusts in near-real-time on the app. During a severe thunderstorm with 55 mph gusts, the Tempest captured the peak gust within 1 mph of our reference, and the real-time graph in the app showed the wind speed spike clearly.

Long-term reliability is where the ultrasonic design really pays off. After 8 months, our Tempest's wind measurements are as accurate as the day it was installed. Mechanical anemometers on competing stations would already be showing wear at the bearings.

The Haptic Rain Sensor: Innovative but Imperfect

The haptic rain sensor is simultaneously the Tempest's most innovative and most controversial feature. Instead of collecting rain in a funnel, it detects individual raindrop impacts on the sensor surface using a piezoelectric detector. The concept is elegant: no funnel to clog, no tipping bucket to jam, and theoretically instant detection of rain onset.

Raw Performance

In practice, the raw haptic readings are inconsistent. Light drizzle is sometimes detected and sometimes missed. Heavy, wind-driven rain can overwhelm the sensor. Our raw haptic readings differed from our manual CoCoRaHS gauge by 15-35% for individual storm events.

Rain Check: The Software Fix

WeatherFlow addresses this with "Rain Check," an algorithm that uses nearby weather stations and radar data to calibrate the Tempest's raw haptic readings after the fact. With Rain Check enabled (it is on by default), monthly rainfall totals typically come within 10% of our manual gauge. Individual storm events can still be off by more, but the trend data is useful.

The catch: Rain Check is a post-processing adjustment that can take hours or days to finalize. If you need real-time, accurate rainfall data during a storm, the Tempest is not the right tool. If you are tracking general rainfall trends over weeks and months, it is acceptable.

Our Take

The haptic rain sensor is a genuine engineering advancement that is not yet mature enough to replace a tipping-bucket gauge for accuracy-critical applications. For casual monitoring, it is fine. For CoCoRaHS reporting or agricultural decision-making, pair the Tempest with a manual Stratus Precision rain gauge for ground truth.

Temperature: Good, With a Caveat

The Tempest uses a passive radiation shield (the horizontal fins on the side of the unit) to protect the temperature sensor from direct solar heating. This design works well when there is any breeze, but on hot, calm days, the shield does not ventilate adequately. We measured temperature errors of 3-7 degrees above actual during July afternoons when winds were below 3 mph.

This is a known issue that WeatherFlow also addresses algorithmically. The app applies a correction based on solar radiation and wind speed readings, which reduces the error to about 2-3 degrees. However, the corrected reading is still less accurate than what you get from a fan-aspirated shield on the Ambient Weather WS-5000 or Davis Vantage Pro2.

In cooler weather or whenever there is wind above 5 mph, the Tempest's temperature readings are within 1 degree of reference, which is excellent.

Lightning Detection: A Standout Feature

The Tempest includes a Franklin lightning detector that reports both the distance and count of nearby lightning strikes. During our 8-month test, it detected lightning from storms up to 20 miles away with distance estimates that generally matched radar observations within 3-5 miles.

The app overlays lightning data on a map, showing individual strike locations and their distance from your station. During an approaching thunderstorm, watching the strikes march closer on the map is both fascinating and genuinely useful for safety decisions (time to get off the boat, bring in the kids, etc.).

False positives from electrical interference (motors, fluorescent lights) were rare after the first week. The sensor seems to learn its local electrical environment and filter out consistent noise sources.

The App Experience

There is no physical console. All interaction happens through the Tempest app (iOS and Android) or the web interface at tempestwx.com. The app is beautifully designed with a main dashboard showing current conditions, a detailed forecast, and quick-access graphs for each sensor. The forecast integrates your station's real-time data with WeatherFlow's machine learning models to provide hyperlocal predictions.

Key app features:

• Real-time data with 1-minute updates
• Historical graphs for all sensors (day, week, month, year)
• Lightning map with distance rings
• Community map showing nearby Tempest stations
• Configurable push notifications for weather alerts
• Dark mode for nighttime viewing

The app-only approach is either a pro or a con depending on your preferences. Tech-comfortable users will appreciate the clean interface and rich data visualization. Users who want a dedicated display on their nightstand or kitchen wall will need to repurpose an old tablet or phone as a permanent display, which works but is not ideal.

Solar Power: It Just Works

In 8 months, the Tempest never lost power. The solar panel charges the supercapacitor during daylight hours, and the capacitor runs the station through the night. Even during a 4-day stretch of heavy overcast with tropical moisture, the station continued operating at its normal 1-minute update interval.

WeatherFlow states that in extreme cases (think Alaska in December), the update interval may slow to conserve power. In the Gulf South, this was never an issue. The absence of battery management is genuinely freeing.

Who Should Buy the Tempest

• Users who want zero maintenance (no cleaning, no battery swaps, no bearing replacements)
• Tech-forward users comfortable with an app-only interface
• Lightning detection enthusiasts (boaters, golfers, outdoor workers)
• People in windy climates where the passive radiation shield works well
• Anyone who values aesthetics and minimal hardware

Who Should Look Elsewhere

• Users who need accurate real-time rainfall data
• Hot, calm climates where passive radiation shields produce significant temperature errors
• Anyone who wants a physical console
• CoCoRaHS volunteers or researchers needing precision rainfall records

Final Verdict

The WeatherFlow Tempest is the most innovative home weather station available. Its no-moving-parts design, solar-only power, and lightning detection set it apart from everything else in the market. The app experience is best-in-class, and the community-powered forecasting adds genuine value over time.

However, the haptic rain sensor is not yet accurate enough to replace a traditional gauge, and the passive radiation shield limits temperature accuracy in hot, calm conditions. If those caveats do not bother you, the Tempest is a remarkable piece of technology that makes weather monitoring effortless.

Rating: 8.5/10

Buy the WeatherFlow Tempest on Amazon