I have always been really interested in observing nature, and that’s part of the reason I love getting lost on my bike. From an early age I was watching animals, clouds, waves and rivers; these natural phenomena seem to blow my mind over and over with how beautiful and complicated they are.
When I was a child, my mum always told me that a ‘red sky at night is a shepherds delight’ and a ‘red sky in the morning is a shepherds warning’. Since childhood that’s always seemed to ring true (more on that in a moment).
On a school camp during my days as a weedy sixth grader, a camp instructor told me that some animals could sense weather change and informed me that we can learn from their behaviour too. He showed me on the first day of camp a colony of ants building their mounds higher, telling me that they always do this when rain is due to come. Sure enough, a day or two later, camp activities were undertaken in rain jackets and soaking wet shoes.
This fascination with weather patterns hasn’t stopped since that day.
Here’s a list of ways you might be able to predict the weather while you’re bike touring. Some are more scientific than others!
1. Red Skies
As stated above, the old saying ‘red sky at night is a shepherds delight’ and a ‘red sky in the morning is a shepherds warning’ seems to be quite accurate for predicting good and bad weather.
Red clouds occur when the sun shines on their undersides at either sunrise or sunset. At these times of the day the sun is low and is passing through a great thickness of the atmosphere which separates the shorter wavelengths of visible light (green, blue, indigo, violet) and flamboyantly shows off the reds, oranges and yellows.
Weather typically moves from west to east, so when the morning skies are red, it is because clear skies to the east allow the sun to light the undersides of moisture-bearing (rain) clouds coming in from the west. Conversely, in order to see red clouds in the evening, sunlight must have a clear path from the west in order to illuminate moisture-bearing (rain) clouds moving off to the east.
2. Animal Behaviour
Humans have followed animal behaviours to predict weather for a long time. Animals are highly attuned to any changes beyond normal air pressure fluctuations and their behaviours often change, which we can use as a signal to big changes in the weather.
As mentioned in my camp experience, ants have been found to build their mounds higher in preparation for periods of rain. Other animals such as insect-eating birds (swallows for example) have a tendency to fly much lower to the ground to get to the lower flying insects. Some birds also use their ability to sense air pressure to determine when it’s safe to migrate, or to cover their nests. Bees and butterflies seem to disappear from the flower beds before periods of rain to protect themselves or their hives.
And finally, although impossible for a bike tourist to gauge, research has also shown that sharks swim deeper in the ocean before storms!
3. Campfire Smoke
To begin this section I’ll explain a bit about air pressure.
Changing weather means changing air pressure. Decreasing air pressure indicates the approach of a low pressure area, which often brings clouds and rain. Conversely, increasing air pressure often means that a high pressure area is approaching, bringing a fine and clear day. Barometers rely on changes in air pressure so that they can predict the coming weather.
Now a bit on campfire smoke. If you observe the way smoke moves around a campfire, you can determine whether air pressure is increasing or decreasing. Smoke will rise steadily from a fire if there is increasing air pressure, bringing fine and clear weather. If the smoke starts swirling and descending, the air pressure is decreasing and bad weather can be expected.
Cloud reading is not so much for predicting weather over the long term, but is good for a couple of hours. During a fine day clouds are white. The higher the white clouds, the finer the day. Storm clouds are generally black, low, and massed in large clusters. If wet weather is approaching, clouds will often form a grey veil.
5. Calm Conditions
Calm conditions often indicate the dominance of a high pressure region. As highs are broad regions of descending air, they discourage the formation of clouds, wind and rain. The ‘calm before the storm’ is sometimes felt when a storm approaching from the west updrafts the westerly surface wind locally. When this phenomenon occurs the storm cell is generally close enough to see.
Moisture in the air causes wood to swell, making doors and windows sticky. This can be an indicator of poor weather.
7. Summer Fogs
Fog is formed when air is cooled enough that condensation is favoured over evaporation. In order for the air to be cool on a summers night, the sky must be clear as cloudy skies often act like a blanket, radiating heat back to the ground.
So if it is cool enough for fog to form, this could indicate a clear day the next day.
See how you go…
The plethora of weather information has taken away most of the need to use environmental cues to assess weather. But for bicucle tourers it’s certainly worth having a good feel for the weather as you sometimes won’t have any access to weather services on your trip!