Sunlight Analysis

Sunlight Hours in San Juan

Sunlight hours, shadow patterns, and solar analysis for San Juan, PR

Interactive 3D Shadow Map

Summer afternoon in San Juan

San Juan

3:30 PM • Summer Solstice

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Interactive 3D shadow analysis map of San Juan. Shows real building shadows based on sun position calculations. Features include: time-of-day simulation, date selection for seasonal analysis, 3D building rendering, tree shadows, terrain elevation, and sun position indicators. Powered by Mapbox GL JS and SunCalc astronomical calculations.

Drag to rotateScroll to zoomWatch shadows move in real-time

Today's Sunlight

March Average

Sunrise

06:34

Sunset

18:31

Total Daylight

11h 58m

Sun Altitude

70°

at noon

Seasonal Extremes

☀️

Longest Day

13.2h

2026-06-21

❄️

Shortest Day

10.9h

2026-12-21

Interactive 3D

Explore Shadows in 3D

See exactly how building shadows fall across San Juan at any time of day or year.

Location
Lat

18.4663°

Lng

-66.1057°

Launch 3D Map

Best Time to Visit San Juan

Month-by-month daylight conditions

San Juan lies in the tropics with consistent daylight year-round. Any time of year offers good sunlight conditions.

Peak Months

Jun, Jul, May, Aug

Shoulder Season

Apr & Sep

Winter

Jan

11.1h

Good

Winter

Feb

11.5h

Great

Spring

Mar

12.0h

Great

Spring

Apr

12.5h

Excellent

Spring

May

12.9h

Excellent

Summer

Jun

13.1h

Excellent

Summer

Jul

13.0h

Excellent

Summer

Aug

12.7h

Excellent

Autumn

Sep

12.2h

Great

Autumn

Oct

11.6h

Great

Autumn

Nov

11.2h

Good

Winter

Dec

11.0h

Good

Excellent (14h+) Great (12-14h) Good (10-12h) Fair (8-10h) Limited (<8h)

Golden Hour in San Juan

Best times for photography

March Golden Hour

Morning

06:34 - 07:34

Blue hour from 06:04

Evening

17:31 - 18:31

Blue hour until 19:01

Best Months

  • 1Year-roundConsistent golden hour length
  • 2Oct-AprMilder temperatures for outdoor shoots
  • 3Jun-AugLatest sunsets for evening shoots

Photography Tips

  • In the tropics, golden hour is brief but intense - arrive early to your location
  • The sun rises and sets nearly vertically, creating short but vibrant color displays
  • Face south during midday for even lighting on subjects
  • Check the 3D shadow map to scout locations and predict light direction

Understanding San Juan's Sunlight

AI-powered insights for your location

San Juan's tropical location (18.5°N) creates minimal seasonal variation, with winter days 2.2 hours shorter than summer. The sun reaches 85° at summer noon but only 48° in winter.

Key Challenges

  • 1Consider local weather patterns that may affect sunshine
  • 2Urban buildings may create additional shadows

Best Months

April through September offers the longest days and highest sun angles in the Northern Hemisphere.

Garden Tips

South-facing gardens receive the most consistent sunlight year-round in San Juan. Consider shadow patterns from neighboring structures when planning outdoor spaces.

Solar Energy Potential

Is San Juan good for solar panels?

San Juan receives approximately 2,420 hours of sunshine annually, making it an excellent location for solar energy. Most residential installations achieve payback within 5-7 years.

Annual Sun Hours

2,420

estimated

Optimal Panel Tilt

18°

facing south

Peak Production

May, Jul, Jun

highest output

Relative Monthly Production

Jan
50%
Feb
60%
Mar
73%
Apr
89%
May
99%
Jun
99%
Jul
100%
Aug
94%
Sep
79%
Oct
64%
Nov
52%
Dec
47%

Installation Tips for San Juan

  • Orient panels south with a 18° tilt for optimal year-round performance
  • Use the 3D shadow map to check for obstructions from trees or neighboring buildings
  • Consider seasonal tilt adjustment: steeper in winter (33°), flatter in summer (10°)

UV Index & Sun Safety

Protect yourself in San Juan

March UV Index

13Extreme

Maximum protection essential. Avoid outdoor activities during peak hours.

UV Index Scale:
1-2 Low3-5 Mod6-7 High8-10 V.High11+ Ext

Monthly UV Index

11
Jan
12
Feb
13
Mar
14
Apr
14
May
14
Jun
14
Jul
14
Aug
13
Sep
12
Oct
11
Nov
10
Dec

Peak UV Months

Apr, May, Jun have the highest UV levels (up to 14). Take extra precautions during these months.

Protection Needed

  • SPF 50+ broad-spectrum sunscreen
  • Full coverage clothing and wide-brim hat
  • Stay indoors 10am-4pm

Outdoor Activities in San Juan

Best times for popular activities

Best Activities in March

🥇

Outdoor Dining

55% match

🥈

Hiking & Walking

55% match

🥉

Beach & Swimming

55% match

Year-Round Activity Guide

ActivityJanFebMarAprMayJunJulAugSepOctNovDec
Outdoor Dining
Hiking & Walking
Beach & Swimming
Photography
Gardening
Running & Cycling
Best months Good Fair Limited Current month

Outdoor Dining

Enjoy al fresco dining during the warmer months with longer evening light.

Best:Nov, Dec, Jan

Hiking & Walking

Mild temperatures and good daylight make spring and autumn ideal for trails.

Best:Nov, Dec, Jan

Beach & Swimming

Peak sun and warmest temperatures during summer months.

Best:Nov, Dec, Jan

Seasonal Sunlight Calendar

Monthly averages throughout the year

MonthSunriseSunsetDaylightSun Angle
January
07:0218:05
11h 5m
51°
February
06:5418:22
11h 28m
59°
March
06:3418:31
11h 58m
70°
April
06:1018:38
12h 29m
81°
May
05:5318:48
12h 55m
88°
☀️June
05:5018:59
13h 7m
86°
☀️July
05:5919:01
13h 1m
87°
☀️August
06:0818:48
12h 39m
85°
September
06:1418:24
12h 9m
74°
October
06:2017:59
11h 38m
63°
November
06:3317:44
11h 11m
53°
December
06:5117:47
10h 58m
49°
☀️

Summer Solstice

13.2h daylight

❄️

Winter Solstice

10.9h daylight

Explore Nearby Cities

Sunlight data for surrounding areas

Frequently Asked Questions

Sunlight in San Juan

1

How many hours of sunlight does San Juan get?

San Juan receives an average of 12.1 hours of daylight per day. This varies throughout the year, from 10.9 hours on the shortest day to 13.2 hours on the longest day.

2

What is the sun angle in San Juan during winter?

During winter solstice, the sun reaches a maximum altitude of only 48.1° above the horizon at solar noon in San Juan. This creates shadows that are 0.9x the height of objects.

3

When is the best time for outdoor activities in San Juan?

April through September offers the longest days and highest sun angles in the Northern Hemisphere.

4

How do I plan a garden in San Juan for maximum sunlight?

South-facing gardens receive the most consistent sunlight year-round in San Juan. Consider shadow patterns from neighboring structures when planning outdoor spaces.

5

What time is golden hour in San Juan?

In March, golden hour in San Juan occurs in the morning from 06:34 - 07:34 and in the evening from 17:31 - 18:31. These times shift throughout the year as sunrise and sunset times change.

6

What is the UV index in San Juan?

The UV index in San Juan varies by season. During summer, UV can reach 14 (very high), while winter UV levels are much lower. Always check daily UV forecasts and wear SPF 30+ sunscreen during peak hours (10am-4pm).

7

Are solar panels worth it in San Juan?

San Juan receives approximately 2,420 hours of sunshine annually. This makes it a good location for solar panels, with typical payback periods of 5-10 years. For optimal performance, orient panels south at a 18° tilt angle.

8

When is sunrise and sunset in San Juan?

In March, sunrise in San Juan is around 06:34 and sunset is around 18:31, giving 12.0 hours of daylight. The earliest sunrise occurs around the summer solstice (05:51) and latest sunset follows shortly after.

9

What is the best month to visit San Juan for weather?

For optimal daylight and outdoor conditions in San Juan, April through September offers the longest days and highest sun angles in the Northern Hemisphere. The shoulder seasons often offer a good balance of pleasant weather and fewer crowds.

10

How long are shadows in San Juan?

Shadow length varies dramatically by season in San Juan. At summer noon, shadows are only 0.1x the height of objects (sun at 85°). In winter, shadows extend to 0.9x object height (sun at just 48°).