Your Marine Weather
Early Warning System™

Please note: The Weathermuffin app has been sunset as of November 2023 and is no longer available.

Download on the App Store

Android Coming Soon!

The most relevant weather at a glance with WxHeadsUp™

Quickly see the most important weather factors expected to influence your specific situation.

See forecast conditions at your future location.

Easily move forward and backward in time to see the weather in context with your anticipated position.

View satellite imagery and synoptic charts overlaid on a map.

Get an unprecedented view of frontal weather systems with the powerful combination of satellite images and synoptic charts.

Enjoy more comfortable passages.

Weathermuffin was designed for you by a fellow sailor.

Plus, stay on top of the latest conditions while away from shore with Iridium GO! connectivity.*

Do I Really Need Another Weather App?

Why Weathermuffin? Why not just use GRiB files?

Current applications tend to offer simply raw data delivery… with a sometimes overwhelming quantity of options for forecast models, GRiB layers, data sources, and so on.

On my single-handed ocean crossing, keeping tabs on the weather was very time consuming, downloading and interpreting data multiple times per day. I was often fatigued, and forgot to check certain things or made mistakes. Plus, the low-bandwidth satellite connection meant there was limited data I could realistically obtain aboard.

Weathermuffin is the first weather app specifically tailored to mariners which considers your specific circumstances. And not just delivering raw data… with its novel WxHeadsUp™ feature, Weathermuffin proactively tells you what to look out for.

With this feature, instantly see the big picture of what you, as a sailor, are concerned about. Then, if needed, go back to your favorite GRiB viewing software for a deeper dive.

Why Does It Work So Well?

Each time you connect, your current position, speed, and course are sent to Weathermuffin’s servers in the United States. We check your specific scenario for weather conditions in your vicinity and along your path for the coming days that may be of interest. The results are reported back to you in secondsway faster than downloading and interpreting a ton of GRiBs!

In fact, in order to get the same information that Weathermuffin provides you in seconds, you would have to download and interpret at least 8 different GRiB layers. How long would that take you?

(Assuming you’re not tired and might overlook something!)

And let’s be honest… How easy is it for you to look at GRiBs and determine when and where you’ll encounter confused seas or wind against current? (And as a result, how often do you actually check for that?)

It doesn’t have to replace GRiB files. Think of Weathermuffin as your early-warning system, your land-based weather assistant, keeping a vigilant watch for the marine weather you care about.

WxHeadsUp™ Alerts

Sustained Wind Speed
Significant Wave Height
Wave Steepness
Confused Seas
Lightning Strikes
Calm Winds

…and many more coming soon!

The steepness of the waves is often of far greater interest to the seaman than the mere heights of the waves.

Graham P. Britton, Captain, Royal Navy (Retired) – source

For details about the available alerts, see Weathermuffin WxHeadsUp™ Alerts.

Synoptic Charts

One thing sailors often overlook about GRiB files is that they’re the raw output of numerical weather models. There’s no human interpretation involved (except your own after downloading!).

On the other hand, Weathermuffin’s synoptic charts are produced by expert, professional meteorologists. As a result, they depict information you won’t find in GRiB files, like the locations of fronts and the ITCZ.

Currently Weathermuffin offers the following synoptic charts (both analyses and forecasts):

  • Surface
  • Wave Height/Direction
  • Wave Period/Direction
  • Wind/Wave
  • 500 MB
  • Sea Surface Temperature
  • Cyclone

* Iridium GO! connectivity requires a Weathermuffin Premium subscription. Additionally, separate hardware and an active data plan from Iridium are required.

The Weathermuffin app is compatible with the Iridium GO! Compatibility with the next-generation Iridium GO! exec is unknown.

“Iridium GO!” and “Iridium GO! exec” are trademarks of Iridium Satellite LLC, which has not endorsed, sponsored, or otherwise affiliated with Weathermuffin LLC.