Home
Weather Dublin
WeatherRadar
RainfallRadar
TemperatureRadar
WindRadar
LightningRadar
Weather News
Editor's Pick
Discover the app
Weather widget
Contact us
Apps
Home / Editor's Pick /

Can seaweed be used to predict rain?

07:00
2 January 2022

Weather myths
Can seaweed be used to predict rain?

Seaweed hangs over edge

The ability to predict incoming weather clearly intrigued civilisation before modern technology arrived, with many myths relating to forecasting. A more outlandish idea is that seaweed could be used to judge imminent rainfall.

The workings are basic to say the least. Hang a piece of dried seaweed outside and keep an eye on its moisture level. If it remains dry the weather will be also be dry and sunny. If the seaweed becomes wet and more flexible it is a sign of rain.

Interestingly enough this can work.

Seaweed can re-hydrate itself repeatedly without ill effect. It also has the ability to absorb atmospheric humidity from the air. Moisture in the air is an indicator of rain therefore if the dried seaweed appears wet it could be a sign of rain.

It is not perfect by any means, humidity also increases in clear weather if a dew is forming. But as a rudimentary guide it has merit.

More on the topic
Split image with Cromer Pier at sunset on the left in soft orange-blue tones and a moonlit Canterbury church with dramatic clouds on the right, lit by a streetlamp.
Sunday 5 April 2026

Your weather - Your shots

Spring captured after the clock change
Map showing wind radar data for a tropical storm near New Zealand. A distinct storm centre with high wind speeds. New Zealand lies to the south of the system.
Friday 10 April 2026

Vaianu brings heavy rain

Tropical storm threatens New Zealand
A green, rolling landscape after rain. Alongside it, a weather map showing a low-pressure system. Indications of further rainfall.
Wednesday 8 April 2026

New low approaching

Morocco bursting to life after rain
All weather news
This might also interest you
Illustration of white and yellow fireworks on a blue background.
Wednesday 31 December 2025

Hello 2026

Happy New Year
plit image showing a double rainbow over a rocky shoreline on the left and sheep grazing in a green field under stormy clouds on the right.
Sunday 2 November 2025

Your weather - Your shots

Mixed conditions on an unsettled week
Split image showing a person in a yellow jacket struggling against strong winds and heavy rain on a street at night on the left, and an Irish wind forecast map on the right with red and purple shading, gusts up to 75 mph, and a wind warning icon, divided by a curved white line.
Saturday 24 January 2026

On this day...

Historic Storm Éowyn arrives
All articles
Weather & Radar

Weather & Radar is also available on

Google Play StoreApp Store

Company

Contact us Privacy Policy Legal info Accessibility statement

Services

Uploader

Socials

facebooktwitteryouTubelinkList