Bowcast

Rainbow forecast for Glasgow

Glasgow, Scotland, United Kingdom: today's strongest rainbow forecast, the best interval to look up, and the week ahead.

55.86°N 4.25°W · about 40 ensemble members · 12 km radius

Today's peak · estimated chance

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Checking about 40 forecast ensemble members for sunlit rain near Glasgow…

Open the live map for Glasgow

Rainbow weather in Glasgow

Glasgow lives under the North Atlantic conveyor: fast-moving showers with bright spells between them, at a latitude where the sun stays low for much of the day. Low sun means tall bows, and "sunshine and showers" is practically the regional forecast. Spring and autumn, when shower trains are busiest, are the best seasons.

At 55.9° north, Glasgow's rainbow geometry changes strongly with the seasons. Summer favors early and late hours; the lower winter sun can keep the geometry open longer, although daylight is shorter.

Wherever you are, the geometry is the same: a primary rainbow forms opposite the sun while the sun is less than about 42 degrees above the horizon. Bowcast's research-informed heuristics give extra weight to clearing showers. The gauge above applies them to ensemble forecasts to predict the rainbow chance for the 12 km around Glasgow.

The rainbow window through the year

in the window sun above 42° below the horizon
At 55.86 degrees north the 42 degree ceiling is never reached from Sep through Mar, so the whole of those days is usable. Jun closes for 7 hours around solar noon.
Share of daylight inside the window
Spring
80%
Summer
61%
Autumn
100%
Winter
100%

Rainbow questions, answered

When do rainbows appear in Glasgow?
Rainbows need sunlit rain with the sun lower than about 42 degrees, so in Glasgow useful windows often occur after sunrise or before sunset on showery days. A study in ZhaoSu, China found that about nine in ten observed rainbows occurred during the hour after rainfall. Bowcast uses that regional finding as research guidance, not a universal rate.
Where should I look for a rainbow in Glasgow?
Always directly opposite the sun: put the sun at your back and look toward the retreating rain. In the evening that means looking east; in the morning, west.
What is today's rainbow forecast in Glasgow?
Bowcast checks sunlit-rain ingredients around Glasgow, hour by hour, for the next 7 days. When ensemble guidance is available, it shows an Estimated chance from about 40 model members, not a probability calibrated against observed rainbow frequencies. When ensemble guidance is unavailable, it shows a Conditions score /100 instead. This page shows the strongest actionable interval; the Now board shows the interval containing the current time.
Can you predict a rainbow in Glasgow?
Not with certainty, but you can forecast the odds. Bowcast works as a rainbow predictor for Glasgow: it reads about 40 ensemble weather members for sunlit rain, checks that the sun sits lower than 42 degrees, and works out which way to face. Read it as an informed estimate of the chance, not a promise that a bow will appear.

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