Sunlight Analysis

Sunlight Hours in Rennes

Sunlight hours, shadow patterns, and solar analysis for Rennes, France

Interactive 3D Shadow Map

Summer afternoon in Rennes

Rennes

3:30 PM • Summer Solstice

Full Screen

Interactive 3D shadow analysis map of Rennes. 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

07:23

Sunset

19:08

Total Daylight

11h 47m

Sun Altitude

40°

at noon

Seasonal Extremes

☀️

Longest Day

15.9h

2026-06-21

❄️

Shortest Day

8.2h

2026-12-21

Interactive 3D

Explore Shadows in 3D

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

Location
Lat

48.1111°

Lng

-1.6743°

Launch 3D Map

Best Time to Visit Rennes

Month-by-month daylight conditions

Rennes experiences significant seasonal variation with 15.9h of daylight in summer vs 8.2h in winter. Plan outdoor activities for late spring through early autumn.

Peak Months

Jun, Jul, May, Aug

Shoulder Season

Apr & Sep

Winter

Jan

8.8h

Limited

Winter

Feb

10.1h

Fair

Spring

Mar

11.8h

Good

Spring

Apr

13.6h

Excellent

Spring

May

15.0h

Excellent

Summer

Jun

15.8h

Excellent

Summer

Jul

15.4h

Excellent

Summer

Aug

14.1h

Excellent

Autumn

Sep

12.5h

Great

Autumn

Oct

10.7h

Good

Autumn

Nov

9.2h

Fair

Winter

Dec

8.4h

Limited

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

Golden Hour in Rennes

Best times for photography

March Golden Hour

Morning

07:23 - 08:23

Blue hour from 06:53

Evening

18:08 - 19:08

Blue hour until 19:38

Best Months

  • 1May-JunLong golden hours, lush landscapes
  • 2Sep-OctWarm light + fall foliage
  • 3DecLow sun angle all day

Photography Tips

  • Summer golden hours are longer and more gradual than in tropical locations
  • Autumn and spring offer the most balanced lighting conditions
  • Face south during midday for even lighting on subjects
  • Check the 3D shadow map to scout locations and predict light direction

Understanding Rennes's Sunlight

AI-powered insights for your location

Rennes's high-latitude location (48.1°N) creates significant seasonal variation, with winter days 7.7 hours shorter than summer. The sun reaches 65° at summer noon but only 18° in winter.

Key Challenges

  • 1Very low winter sun angle (18°) creates long shadows
  • 2Winter shadows extend 3.0x object height
  • 3Large daylight variation (7.7h) between seasons
  • 4Short winter days (8.2h) limit outdoor activities

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 Rennes. Consider shadow patterns from neighboring structures when planning outdoor spaces.

Solar Energy Potential

Is Rennes good for solar panels?

With approximately 1,682 annual sun hours, Rennes has good solar potential. A well-designed system can significantly reduce electricity costs.

Annual Sun Hours

1,682

estimated

Optimal Panel Tilt

48°

facing south

Peak Production

Jun, Jul, May

highest output

Relative Monthly Production

Jan
18%
Feb
29%
Mar
46%
Apr
69%
May
89%
Jun
100%
Jul
95%
Aug
76%
Sep
54%
Oct
35%
Nov
21%
Dec
16%

Installation Tips for Rennes

  • Orient panels south with a 48° 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 (63°), flatter in summer (33°)

UV Index & Sun Safety

Protect yourself in Rennes

March UV Index

8Very High

Extra protection needed. Avoid midday sun if possible.

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

Monthly UV Index

4
Jan
6
Feb
8
Mar
9
Apr
10
May
11
Jun
10
Jul
10
Aug
8
Sep
6
Oct
5
Nov
4
Dec

Peak UV Months

Jun, May, Jul have the highest UV levels (up to 11). Take extra precautions during these months.

Protection Needed

  • SPF 50+ sunscreen (reapply frequently)
  • Cover up with clothing
  • Avoid sun exposure 10am-4pm

Outdoor Activities in Rennes

Best times for popular activities

Best Activities in March

🥇

Gardening

54% match

🥈

Outdoor Dining

24% match

🥉

Hiking & Walking

24% 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:Jun, Jul, Aug

Hiking & Walking

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

Best:Apr, May, Sep

Beach & Swimming

Peak sun and warmest temperatures during summer months.

Best:Jun, Jul, Aug

Seasonal Sunlight Calendar

Monthly averages throughout the year

MonthSunriseSunsetDaylightSun Angle
January
08:5617:36
8h 47m
21°
February
08:1718:25
10h 8m
29°
March
07:2319:08
11h 47m
40°
April
07:2020:53
13h 33m
52°
May
06:3121:35
15h 2m
61°
☀️June
06:1022:04
15h 48m
65°
☀️July
06:2621:58
15h 26m
63°
☀️August
07:0421:16
14h 8m
55°
September
07:4620:15
12h 28m
45°
October
08:2919:14
10h 44m
33°
November
08:1717:24
9h 10m
24°
December
08:5417:09
8h 22m
19°
☀️

Summer Solstice

15.9h daylight

❄️

Winter Solstice

8.2h daylight

Explore Nearby Cities

Sunlight data for surrounding areas

Frequently Asked Questions

Sunlight in Rennes

1

How many hours of sunlight does Rennes get?

Rennes receives an average of 12.1 hours of daylight per day. This varies throughout the year, from 8.2 hours on the shortest day to 15.9 hours on the longest day.

2

What is the sun angle in Rennes during winter?

During winter solstice, the sun reaches a maximum altitude of only 18.4° above the horizon at solar noon in Rennes. This creates shadows that are 3.0x the height of objects.

3

When is the best time for outdoor activities in Rennes?

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

4

How do I plan a garden in Rennes for maximum sunlight?

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

5

What time is golden hour in Rennes?

In March, golden hour in Rennes occurs in the morning from 07:23 - 08:23 and in the evening from 18:08 - 19:08. These times shift throughout the year as sunrise and sunset times change.

6

What is the UV index in Rennes?

The UV index in Rennes varies by season. During summer, UV can reach 11 (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 Rennes?

Rennes receives approximately 1,682 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 48° tilt angle.

8

When is sunrise and sunset in Rennes?

In March, sunrise in Rennes is around 07:23 and sunset is around 19:08, giving 11.8 hours of daylight. The earliest sunrise occurs around the summer solstice (06:10) and latest sunset follows shortly after.

9

What is the best month to visit Rennes for weather?

For optimal daylight and outdoor conditions in Rennes, 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 Rennes?

Shadow length varies dramatically by season in Rennes. At summer noon, shadows are only 0.5x the height of objects (sun at 65°). In winter, shadows extend to 3.0x object height (sun at just 18°).