Rainbow forecast for San Juan
San Juan, Puerto Rico, United States: live rainbow odds for today, the best hour to look up, and the week ahead.
Rainbow weather in San Juan
San Juan sits in the trade-wind belt, the most reliable rainbow weather on Earth. Small, well-spaced showers ride the trades across the area with sunshine pouring through the gaps between them, which is precisely the sunlit-rain combination a rainbow requires. Mornings and late afternoons, when the sun hangs low, are prime time.
Wherever you are, the rules are the same: a rainbow forms opposite the sun, only while the sun is less than 42 degrees above the horizon, and most often in the minutes after a shower moves through. The gauge above runs those rules against live ensemble forecasts for the 12 km around San Juan.
Rainbow questions, answered
- When do rainbows appear in San Juan?
- Rainbows need sunlit rain with the sun lower than 42 degrees, so in San Juan the best windows are the hours after sunrise and before sunset on showery days. Around nine in ten rainbows appear in the hour right after rain stops.
- Where should I look for a rainbow in San Juan?
- 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 the rainbow chance in San Juan today?
- Bowcast computes it live from ensemble weather models: about 40 forecast runs are checked for sunlit-rain conditions around San Juan, hour by hour, for the next 7 days. The live figure is on this page and on the map.
More rainbow forecasts
The best places on Earth to see rainbows →