Bowcast

Rainbow forecast for Singapore

Singapore, Singapore: today's strongest rainbow forecast, the best interval to look up, and the week ahead.

1.35°N 103.82°E · about 40 ensemble members · 12 km radius

Today's peak · estimated chance

…

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

Open the live map for Singapore

Rainbow weather in Singapore

Singapore runs on convective rhythm: heat builds cumulus through the day, showers collapse out of them, and the sun returns fast. That quick alternation of downpour and sunshine, especially in the wet season, produces frequent late-afternoon bows once the sun drops below 42 degrees.

At 1.4° north, Singapore's midday sun often climbs above the geometry for a visible primary bow. Early morning and late afternoon are the most dependable viewing windows through much of the year.

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 Singapore.

The rainbow window through the year

in the window sun above 42° below the horizon
At 1.35 degrees north the sun passes 42 degrees in every month of the year, so the window is a morning and evening band throughout. Feb closes for 7 hours around solar noon.
Share of daylight inside the window
Spring
43%
Summer
56%
Autumn
46%
Winter
48%

Rainbow questions, answered

When do rainbows appear in Singapore?
Rainbows need sunlit rain with the sun lower than about 42 degrees, so in Singapore 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 Singapore?
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 Singapore?
Bowcast checks sunlit-rain ingredients around Singapore, 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 Singapore?
Not with certainty, but you can forecast the odds. Bowcast works as a rainbow predictor for Singapore: 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.

More rainbow forecasts