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
Weather radar showing clouds and showers over Algeria and Morocco. Next to it, a warning map with the rain area in Algeria marked. Surrounding regions mostly sunny and dry.
Thursday, 18 December 2025

Algeria affected

Rain in the desert
Map comparison showing 44 degrees in Indulkana and minus 51 degrees in Olenyok. Coloured temperature ranges show stark global contrasts.
Tuesday, 9 December 2025

Global extremes

Almost 100 degrees difference in temperature
Split image showing a towering storm cloud with rain shafts over the sea on the left and a vivid red aurora illuminating the night sky above residential rooftops on the right, divided by a curved white line.
Tuesday, 9 December 2025

Your weather - Your shots

Autumn captured by you
All weather news
This might also interest you
Split weather map showing UK wind speeds in orange-red shades up to 40 mph on the left and warning levels in green-yellow on the right, with a central wind warning sign.
Wednesday, 22 October 2025

Warnings active

Storm Benjamin impacts the UK
Monday, 25 August 2025

Bank holiday outlook

Warm day turning gusty in places
Mammatus clouds
Thursday, 21 August 2025

Unusual view

Mammatus clouds over Ireland
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

facebooktwittertikToklinkList