howmuchsun

UV index and sunburn time in Punta Arenas

UV peaks at 6.8 (high) in December, around 13:30 local time. At that intensity, untanned skin of type III burns in about 34 min.

How long before you burn?

Sunburn after 34 min unprotected, at peak UV in December
Peak UV index 6.8 High
With SPF 30 17 h if applied properly and reapplied

UV index month by month

Peak value on a representative day of each month, with burn time for skin type III.

MonthPeak UVCategoryPeak atBurns after
January 6.7 High 13:30 35 min
February 5.4 Moderate 13:30 43 min
March 3.5 Moderate 13:30 66 min
April 1.7 Low 13:30 140 min
May 0.7 Low 13:30 357 min
June 0.3 Low 13:30 714 min
July 0.4 Low 13:30 553 min
August 1.0 Low 13:30 229 min
September 2.4 Low 13:30 99 min
October 4.2 Moderate 13:30 56 min
November 5.9 Moderate 13:30 40 min
December 6.8 High 13:30 34 min

Burn time by skin type

At peak UV in December, with no sunscreen.

Fitzpatrick typeDescriptionBurns after
Type I Always burns, never tans 20 min
Type II Burns easily, tans minimally 24 min
Type III Burns moderately, tans gradually 34 min
Type IV Burns minimally, tans well 44 min
Type V Rarely burns, tans profusely 59 min
Type VI Never burns, deeply pigmented 98 min

UV through the day

UV index by month and hour in America/Punta_Arenas local time, daylight saving included. Darker cells mean stronger UV.

UV index by month (rows) and local hour (columns). Each cell shows the rounded value; blank means zero.
Month456789101112131415161718192021
Jan 1 2 3 5 6 7 7 6 5 3 2 1
Feb 1 2 4 5 5 5 5 4 2 1
Mar 1 2 3 4 3 3 2 1
Apr 1 1 2 2 1 1
May 1 1 1
Jun
Jul
Aug 1 1 1 1
Sep 1 2 2 2 2 2 1
Oct 1 2 3 4 4 4 3 2 1
Nov 1 2 3 5 6 6 6 5 3 2 1
Dec 1 1 3 4 5 6 7 7 6 4 3 2 1

none strongest

Other cities in Chile

Assumptions

  • Clear sky. These are upper bounds. Cloud reduces UV, though less than people expect — you can burn on an overcast day.
  • No reflection. Snow roughly doubles your effective dose, and water and sand both add to it. None of that is modelled here.
  • Burn times are indicative. Published minimal erythemal doses vary by around 30% between studies, and individuals within a skin type vary more.
  • SPF assumes proper application. Most people apply a quarter of the amount used in testing, so real protection is far lower than the label.

Full methodology, sources and known limitations